Troubleshooting Trailer Tail Lights not Working on a 2004 Nissan Titan Towing a 2006 Coachman 30 ft

Question:

Running lights quit working. Is there a fuse and if so, where is it located. Also had turn signals but right turn signal and tail light quit, but left side worked. Now left side does not work either only stop light. 2004 Nissan Titan and 2006 coachman 30 ft trailer. Under the hood have two brown relays and one blue relay. Factory tow package Nee your help.

asked by: Steve S

Expert Reply:

The first thing I would do is check for voltage at the trailer connector on your 2004 Nissan Titan. You could use a circuit tester like our part #PTW2993 to test for the correct voltage on the trailer connector. Check out the video I attached that shows how this is done. If the voltage is good, then you know the problem is in the trailer and not your 2004 Nissan Titan.

What you can do is check the trailer side and vehicle side trailer connectors. You will want to look for any dirt or corrosion in or behind the trailer connectors. Corrosion can cause any number of lighting issues.

Next move on to checking the ground connections for each connector to see that they are attached to clean and corrosion free bare metal surfaces.

You can then check the taillights themselves. Again, you are looking to see that the grounds are attached to clean metal surfaces. If all of the grounds check out, there could be a problem with the power wiring to the trailer lights.

You will want to check the wiring from the connector back to the taillights looking for breaks or nicks in the wiring. You can also use a circuit tester like the one you have to test the wiring periodically to determine if there is a break you cannot see.

It is also possible that the relays on the vehicle need to be replaced. You could use Replacement Relays, # C57000, if you find that one or both relays are bad. Use the owner's manual to find the location of the relays.

You could have also blown a fuse like you suspected; you will need to check your owner's manual to determine where the fuses are.