Why Would Stoplights Not Function With 7-Way Round Trailer Wiring Setup

Question:

Hello, All of our fleet trucks are wired for 7 round, so Im going about standardizing all of our trailers to be the same. I have purchased the Pollak 11702 https://www.etrailer.com/Wiring/Pollak/PK11702.html. Which functions go in which locations on the plug? Trailers are wired: White: Ground Black: Clearance/Taillights Yellow: L Turn/Brake Light Green: R Turn/Brake Light Red: Aux Brown: Electric Brakes Im having issues with the brake lights not working.

asked by: Zack M

Expert Reply:

A common issue with the 7-way round connectors is that sometimes the brake light circuit is isolated from the turn signals. My guess is that your tow vehicle has a stoplight circuit dedicated on it's trailer wiring and your trailer has standard trailer taillight circuits where the two are combined.

Probably the easiest solution would be to wire in a 3-2 converter on the tow vehicle wiring so that you can get the circuits combined and your trailer taillights will function properly like with the part # RM-732.

expert reply by: Jameson C