Trailer Brake Lights Dont Work with 2006 Chevy Silverado 1500

Question:

Hi, I have a 2006 Chevy silverado 1500 that I pull multiple trailers with. All my lights on my trailers work except the brake lights. Running and signal all work, but when I apply the brakes the running lights go out. Tried the trailers on my buddies truck and they worked fine. No sure what the problem is. Fyi I dont have a trailer bake controller and I use a 7 to 4 converter. Thank you

asked by: Justin B

Expert Reply:

It may be the adapter you are using or a short or other problem in the 7-Way connector on your 2006 Chevy Silverado 1500. To figure out where the problem is, remove the adapter and use a circuit tester such as # PTW2993 to test the 7-Way while someone sits in the truck and runs through the light functions.

If you find that you are having the same problem doing this test, then the issue is on the vehicle side. Make sure that the trailer connector is clean and free of corrosion inside, where the wires attach, and outside on the pins. A short or bad ground on the vehicle side would explain the problem.

If the truck's 7-Way tests fine, then plug in the adapter and perform the test again by testing the output side of the adapter. If the test shows that the adapter is having the same problem, then the issue is inside of it. The best solution is to replace the adapter with a new one such as # PK12716.

If you do not get a brake light signal at the truck's 7-Way on the pins in the 3 o'clock and 9 o'clock positions, then you can check the CHMSL or stop light fuse on the truck. The brake light signals are on the same circuit as the turn signals, so it is always a weird situation when one works at the other doesn't.

expert reply by: Michael H