Example of a door pin switch used to control dome lights and interior lights.

Wiring Door Pin Switches

This blog post is going to cover how to wire your interior and dome lights.  In most cases you want these lights to turn on when you open a door to your car.  We’ll show you the best way to wire your door pin switches and connect your POWERCELL outputs to your dome lights and interior lights.

Example of a door pin switch used to control dome lights and interior lights.

Example of a door pin switch used to control dome lights and interior lights.

Each door in your car has a pin switch.  Sometimes these are called door jamb switches.  They are very simple devices.  They have one terminal on them.  This terminal originally connected to the ground side of your dome light circuit.  The threaded metal part of the switch connected to your cars ground through the metal part of the door jamb.  These switches work backwards from most people would expect.  When the car door is open, the contact on the switch is closed to ground.  If you think about it, that is what you want.  You want the circuit completed when the door is open.  In the original wiring on most cars, you had battery power supplied to one side of your dome light.  The other side of the light was connected to ground through the door pin switch.  When you opened the door, the switch closed.  This completed the circuit to ground so the dome light came on.

The inputs to an Infinitybox MASTERCELL work the same way.  They get activated when they are connected to ground through a switch.  You can learn more about how the MASTERCELL inputs work by clicking this link.

We do not dedicate a POWERCELL output for dome lights or interior lights.  You can use any of the OPEN outputs that are listed on your configuration sheet to do this.  Simply choose an OPEN output on a POWERCELL and connect that to one side of your dome light circuit.  This link will get you more information on using OPEN outputs.  Connect the other side of your dome light circuit to ground.  Check your configuration sheet and get the MASTERCELL input that corresponds to the OPEN POWERCELL output that you picked.  That input is going to connect to your door pin switches.

In most cases, you will want to have your dome lights turn on if any of your car’s doors are opened.  This is the same if you have a 2 or 4-door car.  To do this, you are going to wire the pin switches in each of your doors in parallel.  You are going to take your MASTERCELL input and connect it to each of the terminals on your door pin switches.  You can splice off of the input wire at the MASTERCELL and run separate wires to each switch.  You can also daisy-chain from one switch to the next in the car.  This wiring diagram shows how to connect the MASTERCELL input for your dome lights to the door pin switches.

Simple Infinitybox wiring diagram showing how to wire door pin switches in parallel to control dome lights and interior lights.

If you open one of your doors, the door pin switch will ground the MASTERCELL input.  The MASTERCELL will send a command to the POWERCELL to turn on the output for the dome lights.  If you open a second door, the input will still be grounded because the switches are wired in parallel.  The dome lights will not turn off until you close all of the open doors.

An added bonus of our Infinitybox system is the ability to theater dim your dome lights.  When the doors close, we can set your dome light to slowly fade away over 10 seconds.  Give our technical support team a call to get this feature on your system.

You can download a PDF copy of this wiring diagram at this link.

If you have questions on how to wire your door pin switches with our Infinitybox system, click on this link to get in touch with our technical support team.

How to wire a parallel switch to control many different switches at once.

Wiring Switches in Parallel

Our Infinitybox system is the most powerful and flexible wiring harness available in the market. Our MASTERCELL inputs are flexible and adaptable for practically any application. A customer just asked this question and we thought that it was a great way to show off the flexibility of the MASTERCELL inputs. The customer is wiring the power window switches in his car. He wanted to know if there was a way to wire a parallel switch that would control all 4 windows at the same time. The answer is “yes” and this blog post will show you how to do it.

Our MASTERCELL inputs work by getting connected to ground. This link will take you to an older blog post that goes through the details of how the inputs work and how to connect a switch to them. Since the inputs work by a ground trigger, this gives you a lot of flexibility with your switches.

This picture shows you how to wire in a parallel switch to control multiple switches simultaneously.

How to wire a parallel switch to control many different switches at once.
Infinitybox wiring diagram showing how to wire a switch in parallel with other switches.

In this example, we’re showing two switches that control the driver’s and passenger’s windows. For the sake of clarity, we’re only showing the front windows and we’re only showing the down action. These switches are labeled Driver Down and Passenger Down in the wiring diagram. You are going to follow the wire colors from your configuration sheet to wire the switches and the power wires that go to the window regulator motors.

To wire in the parallel “master” switch, you are going to connect the MASTERCELL inputs for the Driver’s and Passenger’s switch together and bring them to the parallel switch. The important thing here is that you need to put a diode on each of the wires from the Driver’s and Passenger’s switch. These diodes are electrical check valves. They only let current flow in one direction. They block the flow of current in the other direction. Without these diodes, both the MASTERCELL inputs would be connected together at the parallel switch. They would both turn on with either switch. The diodes electrically isolate the two MASTERCELL inputs so they are operate independently from the individual switches but work together from the parallel switch.

You can source these diodes anywhere. We recommend a 1N4001 diode. These can be purchased easily from Amazon or other on-line retailers. The orientation of the diodes critical. This will not work correctly if they are installed backwards. Note the orientation of the diode symbol in the wiring diagram above. The line on the diode symbol corresponds to the silver line on the case of the diode. Look at the picture below.

Picture showing proper orientation of a 1N4001 diode.

We only show the down action for the power windows in this diagram. We also only show 2 window switches. You can join all 4 inputs together through diodes if you want to control your front and rear windows from a single parallel switch. You can also repeat this for the up action of your power windows.

This same approach can be used for other switches like your lighting. We posted a wiring diagram a while ago showing you how to wire your head lights and parking lights from a single switch using a similar arrangement. You can view that blog post by clicking this link.

Click on this link to download a PDF version of this wiring diagram.

Click on this link to contact our technical support team with any additional questions about wiring your car or truck with our Infinitybox system.

FAST XFI 2.0 Wiring

Electronic Fuel Injection systems have completely changed the way guys control their engines in resto-mods, street rods, kit cars and Pro-Touring builds. All the new systems are simple to install, can control hundreds of horse power and automatically tune themselves. Fuel Air Spark Technology (FAST) has been one of the most significant innovators in the area of EFI systems for the restoration and performance markets. Our Infinitybox plays nicely with any EFI system on the market including the full range from FAST. This blog post will show you how to integrate their FAST XFI 2.0 system with our Infinitybox 20-Circuit Kit.

This blog post is going to walk you through the details of wiring your FAST XFI 2.0 EFI system with our Infinitybox system. Specifically, we’re going to talk about wiring primary power, wiring ignition power, wiring the fuel pump trigger and wiring the cooling fan trigger. All of the rest of the connections between the FAST XFI 2.0 and the engine are covered in their instructions. Please carefully read and thoroughly understand the manual for your EFI system before you go any further. The manual and wiring diagrams for the XFI 2.0 are built into their tuning software package. You can download that by clicking this link.

The following wiring diagram shows all of the connections between the FAST XFI 2.0 and the Infinitybox system.

How two wire the FAST XFI 2.0 EFI system with the Infinitybox 20-Circuit Kit
Infinitybox Wiring Diagram Showing to Interface with the FAST XFI 2.0

Just like most other electrical systems in your car, the XFI 2.0 needs constant 12-volt power from the battery. This connection is the red wire going to cavity B18 in their harness. This wire must be connected directly to the positive terminal on your battery. It is also highly recommended that you have a fuse protecting this wire. The FAST manual recommends a 3-amp fuse in-line between the battery and the XFI 2.0 controller.

Next, you need to provide ignition power to the XFI controller. When your key is in the run position, the Infinitybox system will provide switched ignition power to the XFI controller so that it will control your engine. This ignition power will come from the ignition output from one of your POWERCELLs. Please check the configuration sheet that came with your specific kit to validate the POWERCELL output and wire color. Your POWERCELL output for ignition is going to connect to the Switched Ignition wire on the XFI harness. This is the pink wire going into cavity B17. There is no need to add a fuse to protect this wire since the fuse for it is built into the POWERCELL.

The FAST XFI 2.0 system is smart enough to signal for the cooling fan and fuel pump when it senses that it needs them. You can connect these signals to your Infinitybox MASTERCELL so that your POWERCELLs will control your cooling fans and fuel pump directly. Wiring it this way saves you in the amount of wire you need to run and also eliminates the need for extra relays. Our POWERCELLs have the solid-state relays built into them.

The FAST XFI 2.0 is set up to ground trigger relays for the cooling fan and fuel pump. This is ideal because the MASTERCELL inputs work on ground triggers. We still highly recommend installing diodes between the MASTERCELL and the XFI controller to buffer your Infinitybox system from any stray voltage that could be on the cooling fan and fuel pump triggers. We recommend a 1N4001 diode. These can be purchased from Amazon. The orientation of the diode is very important. If they are installed backwards, the triggers will not work. Please see the orientation in the wiring diagram above. The anode side of the diode should be connected to the MASTERCELL input. The cathode should be connected to the trigger wire on the XFI 2.0 controller.

Your MASTERCELL input wire for the cooling fan will connect to the Fan Control Output wire on the FAST harness. This is the black wire at cavity B10. The 1N4001 wire should be installed per our wiring diagram.

Your MASTERCELL input for the fuel pump trigger will connect to the Fuel Pump Control Output on the FAST harness. This is the black wire at cavity B5 on the FAST harness. Just like the cooling fan input, the diode should be wired per our wiring diagram.

Once you have made these connections to the FAST XFI 2.0 system, follow the manual that came with your 20-Circuit Kit to make the rest of the connections to your ignition switch, starter solenoid, cooling fan and fuel pump.

As you can see, our Infinitybox 20-Circuit is a versatile and power wiring harness system. We can easily interface with any electrical component in your car or truck build. You can download a PDF of this wiring diagram by clicking this link.

Click on this link to get in touch with our technical support team to answer any additional questions about wiring your FAST XFI 2.0 electronic fuel injection system.

Ignition / Starter Switch

Wiring an Ignition Switch

We’ve been helping guys wire their cars for over 10 years. Sometimes we find ourselves skipping over the basics of how our Infinitybox system works and the advantages that it has over traditional wiring harnesses. A customer called us today with questions about wiring an ignition switch to his MASTERCELL. We were surprised to see that we didn’t have a good wiring diagram nor blog post talking about this. This post will correct that.

The MASTERCELL inputs on an Infinitybox system work by getting connected to ground instead of connecting to battery voltage. This has a bunch of advantages over a traditional wiring harness.

First, the MASTERCELL inputs are just triggers to the system. All of the current is carried by the POWERCELLs. Very little current is required at the MASTERCELL. This means that you can use practically any switch to turn on an input to the MASTERCELL.

Second, since practically no current is required at the switch, the MASTERCELL input wires can be very thin. Our standard input harnesses use 22-AWG wire. This keeps the bulk of the harnessing behind your dash to a minimum.

Lastly, you can easily combine MASTERCELL inputs to a single switch to get more advanced functions without having to change anything in the software.

Click on this link to learn more about how the MASTERCELL inputs work.

The ignition switch on your car is probably the most important thing. It lets you start and stop the engine. Most ignition switches work the same way. They all have terminals for power, ignition and starter. Some have an additional terminal for powering accessories. This wiring diagram shows how to connect your MASTERCELL inputs to a typical ignition switch.

As mentioned above, the MASTERCELL inputs work by getting connected to ground. To do this, you are going essentially wire the switch backwards. Instead of connecting the switch to power, you are going to connect it to ground. The first thing to do is connect the battery terminal on the switch to ground. Most switches label this terminal as BAT. Others will label this terminal as B+ or +12V. Look closely at the labels near the terminals to identify the battery terminal. You can either ground this terminal directly to the chassis or you can use one of the black ground wires that is included in the MASTERCELL inputs harness. This ground connection is critical. See our previous posts about how to get good ground connections.

Next, you need to connect the MASTERCELL inputs to the terminals for Ignition and Starter. When the key is in the Ignition position, you need to have power for all of things that run your engine. These include your engine management system, your coils, your gauges and your dash. These are all powered from the Ignition output on your POWERCELL. There is a corresponding MASTERCELL input that turns on this output. Check your configuration sheet to identify these wire colors. Once you know the MASTERCELL input for your Ignition, connect that to the Ignition terminal on the switch. This terminal may be marked as IGN. It could also be marked as RUN. There is an easy way to identify the correct terminal for the Ignition. Turn the key to the Ignition or Run position and measure continuity between the BAT terminal and the IGN terminal. You should have continuity in the run position. It should be open circuit when the key is off.

For the starter input, check your configuration sheet to identify the wire color for the starter. Connect this wire to the ST terminal on your switch.

Lastly, some switches may have an Accessory position on them. This terminal lets you control outputs independently from the ignition. For example, some customers want to be able to power their stereo separately from the ignition so they may listen to music without running their EFI system. The Accessory wires the same way as the ignition and starter. Simply choose an OPEN auxiliary output from your configuration sheet ans connect the corresponding MASTERCELL input to the ACC terminal on the switch. Note that most accessory positions on ignition switches are on in the ACC and IGN positions but off in the START position.

You can download a PDF version of our wiring diagram showing how to wire an ignition switch by clicking this link.

Click this link to contact our technical support team with any additional questions about wiring your car or truck with our Infinitybox system.

Automatic Door Lock Controller


The Infinitybox Intelligent wiring system can easily interface with any other electronics modules sold into the restoration and motorsports markets. By pairing our system with other popular acessories, you can enhance the features and functions of your resto mod, Pro-Touring build, street rod or race car. We had a customer call us today asking how he could get a speed sensitive electrical function on his car. This blog post covers that in detail.

This guy built a custom license plate holder for the back of his car. It has an electrically operated linear actuator and he’s using our inMOTION motor controller to raise and lower his license plate. He has one pair of inMOTION outputs wired to the linear actuator. He wants his license plate to be lowered when the car is moving and raise when the car stops. He wants to use this only for car shows and not when he is driving the car on the road.

He called us asking how he could get this speed sensitive control with our Infinitybox system. We recommended adding the Dakota Digital PAC-3500 Automatic Door Lock Controller to his system to get this to work. The PAC-3500 takes in the signal from his speedometer sender and uses that to control a lock and unlock input. When the vehicle is moving and the PAC-3500 is getting a speed signal, the module sends out a trigger on one wire. When the vehicle stops moving, the module sends out a signal on a different trigger wire. With the PAC-3500, our customer can easily switch his MASTERCELL inputs to lower his license plate when the car is moving and raise it when the car stops. This diagram shows how to wire the PAC-3500 to the Infinitybox System.

Connecting to the Dakota Digital PAC-3500
Diagram showing how to connect the Dakota Digital PAC-3500 unit to the Infinitybox MASTERCELL.

The PAC-3500 needs fused constant power from the battery and a connection to the chassis to ground. It also needs a ignition signal which would come from the ignition output on your POWERCELL. Next, you connect the SPD terminal on the PAC-3500 to the output from your speed sender. Lastly, you connect your MASTERCELL inputs to the LOCK and UNLOCK terminals on the PAC-3500. You must isolate the MASTERCELL from the PAC-3500 using diodes. We recommend a 1N4001 diode. The orientation of these diodes is critical so note their orientation in the wiring diagram.

Whatever MASTERCELL input that you have connected to the LOCK terminal on the PAC-3500 will turn on when the vehicle is moving. Whatever MASTERCELL input that you have connected to the UNLOCK terminal will turn on when the car stops moving. You can set the vehicle speed that turns these on and off by following the instructions in the manual from Dakota Digital. This link will take you to the manual for the PAC-3500.

With the PAC-3500 and our Infinitybox system, you can get speed sensitive control of your electrical system. Raising and lowering this license plate is just one example. You could also use this to lock and unlock your doors with our inMOTION cell. We could set your system to turn off power to your electrical power steering assist above a specific speed. We could use this to raise a wing on the back of the car when you exceed a specific speed. Your options are limitless.

You can download a PDF copy of this wiring diagram by clicking this link.
Give our technical support team a call with specific questions about interfacing the Dakota Digital PAC-3500 to our Infinitybox system to get speed sensitive control of your electronics. You can reach them by clicking this link.

New 4-Button inLINK Remote Functions

We recently made changes to our inLINK remotes.  These changes do a few things.  First, the improve the range of the fobs.  Second, they make the fobs easier and simpler to use.  This blog post talks about the new 4-Button inLINK remote functions.

These new fobs have a more efficient antenna that will let them transmit into the vehicle better.  This will get you better range and more latitude for where you mount the MASTERCELL in your car.

These new fobs use a different processor that lets us get more functions using multiple combinations of button presses.  The original inLINK fobs had a shift button that took you to different “pages” of functions.  This new layout is much simpler and more intuitive to use.

The lock and unlock buttons do exactly what you’d expect them to do.  They enable and disable security, respectively.  If you add our inMOTION cell and are using door locks, we can set these buttons to lock and unlock the car when you enable and disable security.

As a default, the trunk button controls the headlights.  Not all of our customers are using a trunk popper so we assigned the headlights to this button.  If you are using a trunk popper off of your rear POWERCELL, we can set this up for you.  Your trunk will easily open by pressing the button on the remote.

Also in our default set up, the parking lights are controlled by the star button on the remote.

There is a panic function built into the standard configuration.  Pressing the trunk and star buttons together will cause the horn to honk on and off.  The system will continue to honk the horn until you press and release the trunk & start buttons again.

You can download a diagram that graphically shows the different functions assigned to the inLINK buttons by clicking this link.

There are many different custom functions that we can program to your system for control from our inLINK key fobs.  Click this link to contact one of our technical support guys to learn more.

Using Open Outputs

This blog answers a question received from a customer plus shows off the progress on his car.  Mike O just finished his LS3-powered Brunton Stalker Classic.  This is a tribute to the Lotus Super 7You can learn more about there car by clicking this link.  His question was about how to use the open outputs on his Infinitybox 20-Circuit Kit.  He wanted to add a water pump and asked if he could use the any of the open outputs to do this.  He also wanted to know how to wire the MASTERCELL inputs to control his open outputs.  We thought that this was a good question that was worth posting up on the blog.

Before we get too technical, let’s talk about the car.  This is another example of a very unique build and shows how simple yet powerful our Infinitybox system can be.  Mike has been working on this car for a while.  He squeezed a 430 hp GM LS3 engine into this chassis all managed by a custom Speartech engine wiring harness.  Considering that the original Super 7’s came with engines the same size as those used in most garden tractors, this LS will make the Birkin fly.

He handcrafted the rear fenders, back panel, cover and rear diffuser out of aluminum.  He custom made the flared wings out of fiberglass.  On top of all of that, he painted it Lotus Racing Green with a yellow racing stripe.  The LS3 is mated to a T-56 6-speed and the brakes are disc from Wilwood.


Mike wired the car with our 20-Circuit Kit and inLINK.  The benefit to him was simplifying the wiring, reducing the total amount of wire and giving the flexibility with making changes over his project.  He mounted his MASTERCELL and front POWERCELL just forward of the dash board.  Here is a picture of him laying these out.



Okay… now here’s Mike’s question.  He wants to add a Meziere electric water pump to the car.  He originally had a belt-driven water pump.  He wanted to add this electric pump to decrease the load on the engine plus give him more flexibility to cool the car.  Per the manufacturer’s specs, this pump draws 6 to 7-amperes under normal use.  This is well under the 25-amps that a POWERCELL output can supply.

Mike already has the car wired.  With a traditional wiring harness, adding accessories after the fact usually requires running new wires through the car.  With the Infinitybox system, we build in auxiliary outputs that can be used for practically anything.  These outputs can be used for things like extra lighting, multiple fuel pumps, amps, sub woofers and additional cooling fans.  In a typical install, there is 1 open output on the front POWERCELL and 4 on the rear.  Mike simply needs to connect the water pump to the open output on his front POWERCELL.  Then he needs to take the corresponding MASTERCELL input and connect that to a switch for the water pump.  Since he already has the Infinitybox backbone installed in the car, he doesn’t need to run any extra wire through the interior or through the firewall.

The configuration sheet that came with your kit will get you all of the details that you’d need to use these open outputs.  This link will take you to a blog post that gives you more detail on how to read the configuration sheet.  All of the open outputs are set to TRACK.  This means that the output will track the state of the switch.  When the switch is on, the output is on.  When the switch is off, the output is off.  In the case of Mike’s water pump, he can have a switch on the dash what would turn the pump on and off.   He could also wire the MASTERCELL input for his pump directly to the ignition switch so the water pump will turn on when the ignition is on.  You can use this functionality right out of the box with no configuration changes.

We can also custom configure the behavior of these open outputs for you.  One of the most common is to add a timer to the open output used for an electric water pump.  We can set this output to stay on for a period of time after you turn it off.  For example, your electric water pump could continue to run for one minute after the ignition is turned off to help cool down your engine.  Contact our technical support team for more information.

This example shows how flexible and powerful the Infinitybox system can be in your car.  It helped Mike modify the electrical system in his car with minimal changes to add this new water pump.  Thanks to Mike O for asking the question and for sharing the pictures.  The car looks great and we’re proud to be a part of it.

Click on this link to contact our team with any questions about how our Infinitybox system could be used in your project car or truck.

Making Turn Signal Noise

We spend a lot of time educating  customers on what a MOSFET is and why it is better than a mechanical relay.  All of the outputs on our POWERCELLs are controlled by MOSFETs.  They are more efficient than relays, they generate less heat, the have no moving parts, they never wear, we can PWM outputs, etc.  The lists of benefits can go on for hours.  One of the biggest advantages of a MOSFET can also be a disadvantage.  Since it has no moving parts, it makes no noise when it turns on and off.  In the case of turn signals, that can be a disadvantage.

In a traditional wiring system, electro-mechanical flasher modules are used to flash the turn signals.  These are typically bi-metal devices that have been around since the dawn of the automotive industry.  When you turn on your flashers, current flows through a  element in the flasher module.  This heats up a special combination of metals laminated together.  After a short period of time, this element flexes and separates a contact.  When it separates, the current stops flowing and the element cools down.  This lets the element snap back to its starting position which makes the connection again.  The element heats up and the cycle repeats over and over until your turn your signals off.  The mechanical movement of this element in the flasher module is what makes the clicking sound.

This video shows how it works.  Thanks to Chris at Mustang Restorations in Dundee, Illinois for creating this.

You may have noticed in most new cars that the turn signals sound different from most classic cars.  All new cars are using multiplexing technology similar to our Infinitybox system.  This means that they are replacing the traditional flasher module with MOSFET control.  They have tone generators behind the dash that create a synthetic turn signal sound.

Just a quick note about the video above.  If you carefully watch the contacts in the flasher module after Chris removes the cover, you will can see arcing (little sparks) between the contacts as the flasher cycles on and off.  This arcing gradually erodes the contacts in the flasher and causes them to fail over time.  Since our POWERCELL outputs use solid-state MOSFETs, there are no moving contacts to arc and erode over time.  You can flash your turn signals billions of times with no change in their performance.

We occasionally get questions from customers asking how to create a clicking sound when their turn signals are on.  We’ve blogged before about how to wire the turn signal indicator lights on your dash.  This wiring diagram will show you how to get a clicking sound with your turn signals.


You are going to add a relay behind your dash.  This isn’t going to carry any current, you’re just going to use the mechanical action of the relay to make a clicking sound.  You simply tap off of your POWERCELL outputs for your left and right turn signals.  These get wired to the coil of a relay through two diodes.  These diodes are very important because they isolate the two turn signal outputs from each other.  Without these diodes, both of your turn signals would be connected electrically and would turn on together.  These diodes should be 1N4001.  You can easily get them from Amazon.  The orientation of these diodes is critical.  Please note the position of the cathode in the wiring diagram.  This will not work if they are not oriented correctly.

For all standard relays, the coil terminals are 85 and 86.  Connect your turn signal outputs through the diodes to terminal 86, then ground terminal 85 to the chassis.

We recommend a relay like this one.

You can purchase this relay and its terminals at Waytek Wire.  This is a good relay to use because it has an integrated mounting tab.  That makes it easy to mount behind your dash.  It also will help sounds to travel from the relay contacts to resonate your dash.  You want to mount this in a place behind your dash to get good sound transfer.  You may have to experiment with different locations to get the loudest results.

Here’s how this works.  When you flip on your turn signal, the POWERCELL flashes the turn signal outputs.  Power from the outputs flows into the coil of this relay.  This pulls in the relay contact and makes a click.  When the POWERCELL flashes the turn signal off, power is taken away from the relay coil.  The contacts snap back to their rest position and make another click.  This relay isn’t carrying any power, it is just making noise.

You can down a PDF version of this wiring diagram by clicking this link.  

Please let us know if you have any additional questions related to this post or anything else related to our Infinitybox wiring system.  You can contact our technical support team with questions by clicking this link.

Headlights with SPDT Switch

A customer emailed us to ask how he could control his parking lights, headlights and high-beams from a single switch on his dash.  He wanted to use a toggle switch with three positions: down for head lights, up for high-beams and off in the center.  When either the headlights or high-beams were on, he wants his parking lights on.  This is really easy to do with our Infinitybox system.  Check out the details below to see how easy it is to wire your headlights with a SPDT switch.

There are many different types of toggle switches.  The major categories are sorted into the number of positions or throws of the switch and the number of poles or contacts.  A single throw switch was two positions.  These are designated as single throw or ST.  A three position switch has two throws from the center position: one up and one down.  These are designated as DT for double throw switches.

The number of poles on a switch designates the number of contacts.  The most common is single pole.  This means that each position on the switch is connected back to a common point with a single terminal.  These are designated as SP switches for single pole.  The more complicated switch is double pole.  These have two terminals for each position or throw of the switch.   This link will take you to a good Wikipedia article that talks about switches in more detail.

For this application, our customer needs a SPDT switch.  This is a single pole, double throw switch.  The switch has three positions: off in the center and on in the up and down positions.  It has a single pole for each position.  This diagram will show you how to wire MASTERCELL inputs to control the headlights and high-beams off of this Single Pole, Double Throw Switch.

The MASTERCELL input for the headlights connects to the top terminal of the switch.  The input for the high-beams connects to the bottom terminal of the switch.  The middle or common terminal of the switch needs to get connected to ground.  This can go to the chassis or can connect to one of the black ground wires in the MASTERCELL input harness.

When the switch is in the middle position, nothing is connected so the headlights and high-beams are off.  When you flip the switch to the down position, the input for the headlights gets connected to the center terminal, which is ground.  This triggers the headlight input on the MASTERCELL.  To turn on the high-beams, you flip the switch to the up position.

For your parking light input, you need to wire this to both the headlight and high-beam contacts on the switch but there is an important step that you need to follow.  If you were to just wire the parking light input to the headlight and high-beam terminals on the switch, all of the inputs would be electrically connected together.  All three outputs would turn on at the same time in either the headlight or high-beam position.  You need to isolate the headlights and high-beams with diodes for this to work properly.  You need to connect the MASTERCELL input for the parking lights to the headlight and high-beam terminals through two diodes.  These diodes should be a 1N4001 rectifier and these can easily be purchased from Amazon.  The diodes act like one-way check valves.  They do not let the parking light input connect between the headlight and high-beam input.  The orientation of these diodes are very important.  If they are wired backwards, this will not work.  Please look at the wiring diagram for proper orientation of these diodes.

When the switch is flipped to the headlight position, the parking light input gets connected to ground through the diode.  The same thing happens when the switch is in the high-beam position.  The parking lights will turn on when the switch is in the headlight of high-beam position if you follow this wiring diagram.

You can download a PDF copy of this wiring diagram by clicking this link.

If you have questions about this wiring diagram or need specific help wiring your car with our Infinitybox system, click on this link to contact our technical support group.


Our Infinitybox system can used to wire practically any car, truck or vehicle.  It is designed to stand up to the abuse of the harshest off-road, off-highway and commercial vehicle applications.  Here’s another great off-road example.  Sam P. is an Infinitybox customer who was building a JEEP YJ for a customer.  Here’s a picture of the Jeep as he first received it.

… and here is the finished product…

Sam needed a simple electrical wiring system for this Jeep.  He had all of the basics including ignition, starter, head lights, high beams, turn signals, flashers, brake lights, cooling fans and horns.  He also had extra trail lighting that he wanted to add.  The customer also wanted to take this off road so he needed a system that could handle the dust, dirt, moisture, shock and vibration.  Sam purchased our 20-Circuit Kit to get the job done.

His MASTERCELL is located behind the dash.

Here’s a picture of his front POWERCELL.  This is located just above where the transmission tunnel hits the firewall.

Here is a picture of his rear POWERCELL.  He fabricated a pocket in the back by the tailgate to keep the wiring protected.

The finished product is neat, clean and will thrive in the harshest of trail conditions.

If you have a car, truck of off-road vehicle that needs powerful & reliable wiring, check out the Infinitybox system.  Click this link to connect to our technical support team to talk through the details of your project.