Troubleshooting Left Turn and Brake Lights Not Working on a Trailer Towed by a 2004 Nissan Armada

Updated 03/04/2011 | Published 03/03/2011

Question:

I have a 2004 Nissan Armada with a factory installed wiring harnes. I have lost my left dirrectional/brake light in the connector and along the wiring harness. After reading several other post my assumtion was a bad directional relay, I watched your video on the instillation of the wiring harness for the 2006 titian and have a similar fuse box with relays in them some brown and 1 blue in attempting to trouble shooting my problem I pulled the relays out and tested my trailer connection which was unaffected by the relay removal , the legend on the 3 different fuse covers were no help , any thoughts? thanks

asked by: Kevin

Expert Reply:

The problem you are experiencing could be associated with a bad ground and/or corrosion in the trailer side or vehicle side connectors. I would start by cleaning out any dirt or corrosion from the front and back of the trailer connectors to see if that fixes the problem.

If not, I would move on to checking the ground on the trailer. Make sure the ground from the trailer plug is attached to a clean metal surface. Then you can check the grounds at the tail lights. On many trailers, the tail lights ground through the mounting studs. These, too, will have to be connected to a clean and corrosion free bare metal surface.

You can also check for a good ground on the vehicle side plug. If all the grounds check out you can trace the wiring back on the trailer side to check for a loose or broken wire and then do the same on the vehicle. If everything checks out it may still be the relays. The reason it may work when you test it at the 7-Way but not when the trailer is connected could be that without the relay, the extra load from the trailer lights renders it inoperable.

expert reply by: Michael H