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.