Is there a Special Trailer Tail Light Bulb for Turn Signals, Brake, and Running Lights on One Bulb

Question:

Is there a special bulb for a boat trailer that will signal, stop and running all in one or is it the wiring not the bulb that does the function?

asked by: Sylvia

Expert Reply:

Trailer tail lights have a combined circuit for turn signals and brake lights and a separate circuit for the running lights. Because of this type of system you would not be able to get all the functions on a single circuit. That type of wiring is fairly complex and is primarily found on German vehicles (Volkswagens in particular) but not all.

But even on trailer stop, tail, and turn signal lights the functions are all on one bulb, sometimes 2 depending on the light. But there are still 2 separate wires; one for turn and brake, and one for running lights.

expert reply by: Michael H