Ok... need some help.  The lights on one side of my trailer don't work, but the problem is not the trailer.  Hooked it up to a buddy's truck last week and all lights worked fine and dandy.  We got under the truck and all wires appear to be fine.  Am I going to have to rewire the lights to my trailer hook up?

I have a nice hook up.  Not sure what it is called, but I have a round attachment that plugs into the truck, and I then plug the trailer wire into the round attachment.  I have no idea what any of them are called.  Help

Let me give you a heads up to make life easy when it comes to wiring on your trailer and in your boat. Most the wiring in boats and on trailers are a cheesy quick connect setup. I took the time a few years ago to replace all my connections by soldering them and putting shrink tubing over them all. I have not had a problem with either trailer or boat since. It was time consuming but, well worth the effort.

justfishin idea is one I do always  8-)

Most electrical problems are the ground  

Your best ground will be your trailer hitch. So don't get reel bend out of shape until you tow a little bit make a couple turns get that ball shined up a bit. Then check your lights.

Garnet

A bad ground can make trailer lights do some funky things. :-?  Ithought I had gremlins for a while until I changed the ground. ;D

I had that problem last summer.  It turned out to be a blown fuse in the engine compartment of the truck.  I drove a 98 Chevy Blazer.  I had checked all the connections and wires on the truck and trailor and finally found the fuses under the hood. Sure enough, one of the fuses had blown.

L-Train,

You are going to have to verify the the wiring and the connector on your vehicle are correctly wired if this is the first time using it. If they worked normally before this problem occurred I would check the connector mounted on your truck and verify that the contacts are clean and free from corrosion. Get some electrical contact cleaner and spray the connector's contacts and brush them with a stiff nylon brush. Don't use a metal brush, you don't want to short anything out. Also, get some di-electric grease and use it on the contacts to protect them from corrosion. If this doesn't work I would follow the routing of the wiring on your truck's connector to the other connectors that it connects into and check them. I would use the same process with them as well. If the connector is "hard-wired", spliced into the truck wiring, I would check and make sure that the connections are good by removing the electrical tape or covering and verifying that the wiring is not corroded, green or white residue on the exposed wires will cause problems, undo the wiring connections and then clean them with the contact cleaner, grease them with the di-electric grease and use the method that "justfishin" stated to reconnect them. If you aren't familiar with soldering I recommend taking your vehicle to an establishment that can "hook you up" ...no pun intended. Perhaps an RV or boat sales store.

There are trailer electrical hookups that connect directly into your truck's existing connectors on later model vehicles if you find that your wiring is hard wired versus through the connectors harness.

Another thing to look at is whether your trailer hitch has a positive ground to the frame of your vehicle. Quite often paint on the vehicle frame and paint on the hitch frame inhibits a good ground. Mounting a heavy ground wire from the hitch assembly to the frame may help make a more positive contact. But I would be more concerned about the wiring of the connector than I would the hitch, especially if you have a removable hitch tongue. They aren't made to ground well.