Troubleshooting a Curt Trailer Harness, Brake and Left Blinker Not Working

Updated 06/20/2012 | Published 06/16/2012

Question:

This connector has been in use about five years but now the drivers side. Break and left Flasher do not work. Testing at the connector with a spare trailer light it does not work but light works when connected to the green wire. Yellow wire has no cuts all the way back to the where it connects to honda. Disconnected and reseated - no better. Says it is curcuit protected. Where are protectors. Yes lights on car work fine.

asked by: Charlie

Expert Reply:

The first thing I would do is test for voltage between the tail light connectors and the convertor box to see if the correct voltage is going into the box, but none is coming out on the green wire. This will tell you if the problem is in the box or if it is in the connector.

If you see voltage on the brake and left flasher circuit going into the box, but none coming out then you know the problem is in the box. If there is no voltage on the circuit going into the box either you know the problem is in the connectors. I suspect the problem is in the box since you said your vehicle tail lights still function.

The circuit protection that is on this product is inside the box, basically the box is setup so that if there was a short on your trailer it would not short out the tail lights of your vehicle. The problem, as you may have found out, is that the box will get damaged instead.

expert reply by: Jameson C