Trailer lights not working on hook-up?

jjenkins130910

Hi, I just recently bought a used 2004/2005 Tab trailer and getting ready for my first camping trip. I can't seem to get the trailer lights working when I hook it up to the 4-pin to 7 pin converter. Is there some trick I'm missing? Should I check the fuses?

 

Jenny

Michigan_Mike

Hi Jenny,

You probably do not have a good ground connection as in many instances if the ground wire is not hooked up properly or is missing you will get no lights at all.  What you need to do is start at your vehicle first and have the wiring checked out or tested to verify that the problem isn't with the vehicle wiring.  Once you have established that the vehicle wiring is correct and that the wiring harness works you can move on to trouble shooting the trailer harness wiring.   If you are using a 4 pin to 7-pin adapter the adapter will probably need to be grounded to either the tow vehicle or trailer.  And quite frankly if it were me, I would  spend a few bucks and have someone wire in a 7-pin female receptacle on the rear of your tow vehicle as that will simplify things and you can charge the trailer battery off the vehicle alternator if you have the installer wire in a separate feed wire back to the connection on the 7-pin adapter.  Ultimately that will make your life on the road easier and eliminates having the 4-pin adapter on your vehicle as all that does is run your tail lights and blinkers.  

You can certainly check for a blown fuse (look next to the battery and see if there is a wire coming off the positive terminal) but it depends on who wired the 4-pin harness and whether or not they just wired into your rear tail light harness.  Another thing you can do to verify the trailer wiring is working correctly would be to have a friend or neighbor (who has a 7-pin connector on their vehicle) stop by and plug the trailer harness into their vehicle to test the wiring and turn signals, etc.  

This guy has a good article on trouble shooting trailer lights and you will need a 12 volt tester (available at Walmart in their automotive section) that will allow you to see if you are getting voltage to the trailer wiring harness and to the rear of your tow vehicle.  The problem with these troublesome issues is that it could be about anything, but with no lights at all, it is more than likely not having a good ground on either the TV or trailer.   If you are not knowledgeable in this area you should probably have a friend repair it who is, or take it to someone who can evaluate and fix the problem.  

Here is a video that will help out and give you an idea as to how to fix your problem:  

https://www.youtube.com/watch?v=jeOswVvWs20#t=197