How to Check Brake Switch Wire to See if it Goes to Ground When Installing Curt Brake Controller

Question:

In the instructions for connecting to the brake light switch at the brake pedal it says to find the wire that is activated when the pedal is pushed. I have found the only wire that is activated when the pedal is pushed and it is a white wire. It then says to be sure that the wire is not grounded when the pedal is up as this will destroy the controller when the manual control is used. How does one know if this wire is grounded when the pedal is up? My vehicle is a 1999 Oldsmobile Bravada.

asked by: Mitch M

Expert Reply:

I spoke with my contact over at Curt about how you can test to see if the wire goes to ground when the pedal is up. You will need a multimeter, such as # PT89ZR, and set it to test for resistance (ohms). With the pedal up the correct wire will have a few ohms of resistance (he said 5 or 6 usually). If it shows zero then that means it goes to ground when the pedal is up and it is not the correct wire.

He also added that it probably is not going to be an issue on your 1999 Olds Bravada but it is always a good idea to double check.

expert reply by: Michael H