Brake Light On Trailer Stays On With Vehicle Not Connected

Updated 02/27/2019 | Published 02/26/2019

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Question:

I have a 12v car battery in camper with extra red wire sending power to Hopkins breakaway system. Problem is when red wire connected to battery, right rear brake light stays on even when not connected to vehicle. I remove the Hopkins system and its still on. Could the brake be engaged causing the light to light ? I live in a cold climate.

asked by: Dan

Expert Reply:

The Hopkins Engager Push-To-Test Trailer Breakaway Kit part # 20099 should not be tied into the brake light circuit on your trailer at all, only the brake output circuit so this is not part of the problem. I have attached a wiring diagram of how a breakaway system should be wired for you. Also, in certain states the breakaway battery must receive power from the 12 volt circuit on the 7-way so you may want to consider rewiring your breakaway system.

The issue you have with the right brake light staying on even when not connected to the tow vehicle is a short between the right brake signal wire and most likely the 12 volt power wire to the 7-way or the auxiliary battery on the trailer. This wire will need to be checked for shorts but the most likely issue is corrosion inside the trailer connector. If it is corrosion inside the trailer connector then you can use part # 11755 to prevent this in the future. If you can't find the break in the wire then it can be replaced with part # 16-1-1.

expert reply by: Conner L