Trailer Light Problem

While on the way to the lake yesterday, somebody pointed out to me that my brake lights, and blinkers were not working. The lights work...just no brakes, no blinkers.....I hooked it up to both my vehicles when I got home, so I ruled out the truck being the issue. Any ideas. (Sorry, I am electricly challenged)

Have you recently changed adapters? Sometimes different plug adapters will make a difference with this issue.

No, the trailer is less then a year old....I also noticed tonight that one of my rear lights is half full of water.. I do have an extral adapter if I do need to change it ..

Check your ground wire. It will be the white wire. Then go from there. I just got done redoing mine. Graig I think your in Modesto if ya need help e-mail me at wakesquid420@yahoo.com and I will come by and help you out.

Is the ground wire (the white wire, on the odd contact of the flat connector (bare on the car side, covered on the trailer side) connected at both ends?

Many trailer light installations try to save a tiny amount of work by using the hitch as the ground. The problem is that a receiver (removable) style hitch is very unreliable at making a decent electrical connection.

Without a ground all sorts of funny modes of operating can result.

If you have a light that is half full of water then it is most certainly bad, or soon will be!

Do you know that the lights ever worked? Some people just hook up and go without ever checking. It is always a good idea to make sure you have left turn, right turn and tail light before you take off. If nothing else you can adjust your driving a bit to compensate for a blinker not working.

I wouldn't rule out the truck as being the issue until you saw the truck operate a known good trailer. I highly recommend getting yourself either a multi-meter or a 12 volt test light. The test light is best for this. The test light looks like an ice pick with a wire coming out the handle and a light bulb inside the handle. You clip the wire on ground then poke the point into the circuit you want to test. If the light lights, you have power!

To test your truck's light connector clip the test light wire onto the exposed connector on the truck's light connector (ground) then poke the tip into the covered connectors. Since the possibilities are few you can just test them all.

Turn the head lights on, identify the tail lights (should be the covered connection right next to the bare one. Now turn the left turn signal on, test the next hole over. Right turn is one more over from that. If you have a five pin connector then back up lights will be the last one.

If it is not the ground and the output of the truck is okay then either the turn signal/brake light bulbs are burned out (unlikely on both sides but possible) or the wiring is damaged.

It is not uncommon for a loop of wire to drag the ground and wear through. Check the wire between trailer and truck. I have also seen cases where the wiring ran under the trailer frame and got scraped off when the trailer high centered so follow the wires from the front to the back. If you find a break in the wire splice it back together, hopefully in a way that the problem won't repeat.

Check the adapter as well. On my adapter, the ground wire was disconnected inside the housing but gave an intermitent connection - thus causing all sorts of confusion.