All Trailer Lights Work Except Turn Signals w/Curt Wiring Harness Installed on 1991 Suzuki Sidekick

Question:

We hooked the converter box up as per instructions on a 1991 suzuki sidekick LX, but we have no turn signals. running lights and brake lights work great. any solutions? All lights are working on the vehicle.

asked by: Mike I

Expert Reply:

When just the turn signals are not working on the trailer, it is a bit of a strange situation because the brake lights and turn signals are on the same circuit. So, if the turn signals or brake lights are working then the other function should be as well. But there are situations when this can occur, for example on a vehicle that has combined brake and turn signals but also has a dedicated brake light wire.

If your Sidekick has combined brake and turn signals, then you would attach the yellow wire to that combined circuit on the driver side and the green wire to that combined circuit on the passenger side. The red wire would be grounded with the white wire.

If your Sidekick has separate bulbs for brake lights and turn signals, then you would use the yellow and green wires for the turn signals and the red wire for the brake lights.

If the Sidekick has combined running lights and brake lights then you would use the yellow and green wires for turn signals, the red wire for brake and running lights, and ground the brown wire with the white wire.

In order to figure this all out you would need to test the taillight wiring with a circuit tester like # PTW2993 if you need it. Have someone run through the functions while you test to determine the wire functions.

If you have installed everything correctly and the turn signals still will not work, then disconnect the trailer and use the circuit tester to test the vehicle side 4-Way. If the turn signals are not coming through there, then check the wires leading into the converter box. If they are correct going in but not at the 4-Way that indicates a problem with the converter, and it will need to be replaced.

If everything checks out on the vehicle, then the issue must be on the trailer. Make sure the trailer connector is clean and free of corrosion. Make sure the main trailer connector ground and all the light grounds are attached to clean and corrosion free bare metal surfaces. If the trailer has an aluminum frame, tilt bed, or folding tongue then running jumper grounds from the lights to the main trailer connector ground might help.

If you do need a replacement harness, you might be interested in # HM41245 which just plugs into a factory connection point. I have included some FAQ links that should also help.