I recently upgraded from single to dual master cylinder, in doing so I got rid of the pressure brake light switch and placed a switch on the brake pedal. I wired it up and it works, but too much. The brake lights will not turn off regardless of the brake pedal being depressed or not. I've tried to switch the two wires around and still got the same result. I don't know if there is a difference in how the switches work. Might be a not understanding the workings of it but my logic was a switch is a device that is waiting for the connection to be completed and it will do what ever you wanted it to.

 

 

Shane Do you have it placed so that the arm in the switch comes all the way out when the pedal in not being used?

My rig
Ford Truck Picture by jowilker | 813147 | Ford-Trucks.com


John

 

The switch doesn't have any polarity. It's just a normally closed device, held open. You have a hot wire on one contact (doesn't matter which one) and you have a signal wire on the other.

As long as the white plunger on the switch is being pushed in, the contacts will be held open which will break the circuit path through the switch. Once the brake pedal is pushed forward, the plunger should move outwards and close the contacts, completing the circuit to the tail lights and turning on the brake lights.

If the pedal is at its static position (not being applied) and the brake lights won't go off, it either means the switch plunger isn't being pushed in far enough to open the switch contacts or, it means the brake switch itself is bad.

It looks like in your photo the white switch plunger isn't pushed in far enough. It also looks like you don't have any adjustement left to run the switch out any more than it is towards the pedal support.