Brake Light Overrides Blinker on Trailer Towed by a 2012 Chevy Cruze

Question:

Hooked it up and everything works, running lights, blinkers, brake light. But when you have a blinker on and apply the brakes the brake light over-rides the blinker. The blinker stops and is on steady like a brake light. The car blinker and brake lights are still functioning properly

asked by: Brian K

Expert Reply:

This sounds like a ground problem. The blinker on the side that is activated should keep blinking while the other side lights up as a brake light. If the opposite occurs, the wrong side blinks then you may have the connectors switched where they plug into the vehicle.

The connectors with the red and yellow wire go on the driver's side. Green and white on the passenger side.

If that is all connected properly, and the unit is grounded to a clean and corrosion free bare metal surface then go ahead and use a circuit tester like # PTW2993 if needed to test the 4-Way. If all of the signals are coming through properly then you know the issue is on the trailer.

If the signals on the 4-Way are not correct, then check the wires going into the converter. If they are correct going in but not right on the 4-Way, then there is a problem with the converter, and it will need to be replaced. If the signals are not correct going in, then there is a problem with the vehicle wiring.

If you eliminate the vehicle side as the issue, then you can move on to the trailer. Make sure that the main trailer connector ground is attached to a clean and corrosion free bare metal surface. Do the same with each of the trailer lights. If you have a tilt trailer, folding tongue, or aluminum frame you will need to run jumper grounds from the lights to the main trailer connector ground.

I have included a link to an FAQ article that should also help troubleshoot the wiring problem.

expert reply by: Michael H