What are the Wire Functions for Transit LED Stop/Turn/Side Marker/Tail Light

Question:

I have a 1991 Scamp 16ft my wiring coming out of the trailer is red,black,white and green, the lights have red,black and white, what do I do with the green I have no running lights now.

asked by: Russ

Expert Reply:

On Transit LED Stop/Turn/Side Marker/Tail Light, # STL90RB, the white wire is ground, the red wire is for brake lights and turn signals, and the black wire is for running lights.

It sounds like your trailer may have had separate turn signals from the brake lights. This would explain the 4 wires instead of 3. You will need to verify the functions of the trailer wiring using a circuit tester such as # PTW2991. Test each wire while the trailer is connected to the tow vehicle and have someone run through the different lighting functions while you are testing the wires.

That should tell you the green wire function. If you do have separate turn signals from brake lights you would either need to add an additional turn signal light or replace the tail light with one that is set up with separate turn signals and brake lights.

expert reply by: Michael H