Tail Light Fuse on Truck Keeps Blowing When Trailer Wiring is Connected and Then Trailer is Coupled

Updated 10/18/2017 | Published 10/17/2017

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Question:

My trailer lights work properly when i connect my truck and trailer harness without the trailer touching my hitch. when i connect the trailer to the hitch it blows the tail light fuse in my truck????

asked by: David G

Expert Reply:

There are a few things that you will want to check since your tail light fuse keeps blowing when you couple your trailer.

Start off by checking the connector on your truck and your trailer. Make sure that it is clean and free of debris and corrosion as that can cause power from other circuits to bleed over to the running lights. Using dielectric grease like part # 11755 on your connectors can help prevent water damage and corrosion.

If the connectors look good then you will want to check the grounds and the wiring on your trailer. Make sure that the grounds are secure and connected to a clean, bare metal surface as even some paint can cause issues. Check the wiring for the running lights and look for any places where the wiring is damaged, bent, exposed, or corroded and replace accordingly. You can use bonded 16 Gauge wire # 16-4B-1 or single 16 Gauge Wire # 16-1-1 as well as some Butt Connectors # DW05744-5 to replace the wiring.

I have attached some helpful articles for you to check out as well.