Troubleshooting Lights Of New Taillights On 5'x8' Trailer Working At Incorrect Times

Question:

I put new rear lights on the 5x8 utility trailer. they have bulbs and a white, brown, yellow, and green wiring. this truck has the original factory connector. the lights all work on the truck. I removed and cleaned the truck white gnd to chassis cleaned to bare metal and added a ground connector to the tongue. there was one at the drivers bracket with no white wire on the passenger light. The blinkers come on at the same time? on the trailer. and I noticed the truck turn signals were coming on at the same time dimmly The brake lights are on when I push on the brake pedal the brake lights go off on the trailer. I have parking lights! Could this be one of the tow package relays?

asked by: James M

Expert Reply:

This sounds like the typically tail light replacement where you hook stuff up color to color, and not function to function.

You need to verify with a circuit tester like # PTW2993 that the connector on your vehicle is working correctly first. If you have all the correct functions on the correct pins (check out the attached help article) then the issue is with the trailer wiring, but if your factory connector is not working right then it's something on the vehicle side.

Assuming the vehicle connector tests correctly, use the test light to test the wiring powering your new lights, and make sure that the wire function is correct to the function of the wire on the light.

On your tail lights the white is ground, brown is running lights, yellow is the left(driver) turn signal/stop, and green is the right(passenger) turn signal/stop.

I'm willing to bet that some wires got mixed during the install, but a quick test with a circuit tester will confirm or deny this.

Let me know what you find and I can be more specific on what you'll need to do to get the issue fixed.

expert reply by: Samuel C