What is Needed to Wire Up 4-Way if Vehicle Has Turn Signals and Brake Lights on Different Circuits
Updated 01/12/2026 | Published 09/02/2024
Question:
2005 Chevy Silverado very old truck and the original wire harness is old and corroded and has problems up into the main wiring of the truck. So, I want to install a 4 way flat and it works the running lights brown wire, the left turn signal green wire, and the right turn signal yellow wire. The problem is my brake lights dont work. I have a 4 way flat on the trailer works great when other tow vehicles are hooked up to it running lights, tail lights, turn signals, brakes all work. My problem is the new 4 way Im trying to hook up on my old Silverado. It appears that the turn signal and the brake lights on the Silverado are separate while the turn signals and the brake lights on the trailer are combined. How do I get powerinch to my brake lights on the trailer from the Silverado using the 4 way flat pin connector?
asked by: Mark
Expert Reply:
Hey Mark, what you need is a taillight converter like the part # HM48847 which is designed to take your separate taillight circuits and combine them like what trailer wire circuits are designed for.
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on Custom Fit Vehicle Wiring
Jameson C.
1/12/2026
Hey Mark, how did things go after adding the taillight converter to your Silverado wiring? It’d be great to know if that solved the brake light issue on your trailer. Your update could make it easier for others with older trucks to get their lights working right.