Brake Lights on Magnetic Trailer Lights Don't Function But Turn Signals Do

Question:

I have a 1988 itasca suncruiser RV, it has separate brake lights and blinker lights on the back , it has a round 7 prong tow package. I bought a set of 4 pin straight hook up trailer lights amd a 7 to 4 adapter to put on trailer lights on the back of my Ford explorer 1996 and wired according to directions. All of the lights are functional except the brake lights on the trailer light setup. Its very frustrating please help.

asked by: Gentry

Expert Reply:

I assume by "4 pin straight hook up trailer lights" you have a set of magnetic trailer lights like the Heavy Duty Magnetic Tow Lights part # TL21RK. If that is the case then the only things that would cause these not to function properly when using a 7 to 4-way adapter like the Pollak 7 Pole to 4 Way Connector Adapter part # PK12716 is if the motorhome's 7-way is not wired correctly, there is a bad ground on the 7-way/ lights or the lights themselves are faulty.

I recommend you check the right turn/stop and left turn/stop pins inside the 7-way. If the pins are only active when the turn signals are on then most likely the brake/turn signals are not combined. If this is the case then you will need to do this with the Roadmaster Brite-Lite Wiring Converter part # RM-732.

If the pins are active with both the stop and turn signals applied then make sure the configuration of the pins inside the adapter correspond to that of the 7-way. If these steps don't fix your issues then it might be better for you to take the motorhome to a professional.

expert reply by: Conner L