bigjohn767

I have installed a Curt 56735 wiring harness without the relays. There is a relay in the fuse box which is supposed to indicate that the trailer light package is installed so I didn't put in the two relays that came with package (this was in the instructions). I have a new trailer and the driver side turn signal does not work. The passenger side does work. I can switch the lights and the same thing occurs, driver side doesn't work but passenger does. This eliminates the lights. The yellow (driver side wire) has continuity. A plug in harness checker shows the vehicle output to the trailer lights working correctly. I ran voltage tests on both green and yellow wires when the turn signal is on and the voltages fluctuate the same. I have tried a new wire harness from the trailer. Same results. Tail lights (brown wire) work fine. Passenger side turn (green wire) works fine. Driver side turn (yellow wire) doesn't. Stop light on driver side doesn't work. One quirk we noticed is the driver side light will give a short blink when the turn is activated but then nothing.

Could the factory installed relay be bad? Should I have installed a different wiring harness in the vehicle? Any help would be appreciated!