Troubleshooting Trailer Tail Lights Not Working When Brake/Turn Lights Work
Updated 03/05/2019 | Published 03/03/2019
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Question:
HAVE SIGNAL BRAKE FLASHERS BUT NO TAIL LIGHTS HAVE NO POWER AT THE PLUG CANT FIND A BLOWN FUSE HELP
asked by: KIRBY G
Expert Reply:
Since you have brake and turn but not taillights, the issue can be a fuse, a relay, bad wiring, or a weak connection. I recommend you first start with the wiring connection by cleaning it up with some sandpaper or steel wool, and then testing the pin for power.
If you don't have power, I recommend first checking your ground connection at the trailer plug. A weak ground connection can cause some functions to work and others not to work. Next, I recommend checking your owner's manual for a fuse or relay location that has to do with trailer taillights/running lights. If there is nothing in the fuse or relay information for trailers, then I recommend tracing your wiring from that pin location back using a circuit tester like # PTW2993 probing the wire every few feet. When you find the short, replace the wire with # 16-1-1 sold by the foot and butt connectors # DW05744-5.
If you tract to a converter box or module and you test signals coming in but not coming out, then the module will need replaced.
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