Trailor lights

[Fathead]

Question for you wizards,

I have not spent anytime looking at this problem yet, but I thought I would throw this out to you.

Coming home 2 nights ago, I noticed that my trailor lights on the drivers side were completely out. The passenger side lights were working. I figured it might be a cut or pinched wire, but it doesn't appear to be.

Question, are trailor lights wired in series? I wouldnt think so, but I suppose it is possible. I haven't checked the bulbs yet, but if the trailor is wired in series, and a bulb is spent, I guess that would explain why all lights on one side are out.

Your feedback would be appreciated.

[pulsar_nx]

I think they are wired in parallel. One wire for the brake, and another for the blinkers, with the trailer itself being the ground.

[Valv]

They are not wired in series. If one light bulb goes out, it won't shut off whole side.
You probably have some wire problem, or connector problem.
Clean and inspect them, the side markers feed from same wire of tail lamp, which is the brown color.

[chunkytrout]

Valv is right. Check first at the connector. Look for corrosion (it doesn't take much). If your trailer has side markers, inspect that next. Take it off if you can and look at the copper tabs on the back of the fixture. Make sure they're in good shape. A voltmeter will come in handy.

chunk

[Fisher Dave]

Umm .. could just be the bulbs?

I would replace them 1st and go from there. You can check with a voltage tester of some sort to see if you have power to the tail light socket when your changing bulbs.

[Valv]

One thing for sure, never underestimate ground.
I fell for it many times, and still gets me.
If you are checking lights from home, hook up your trailer, go around the block once, to be sure it grounds well through ball, hitch and truck.

I don't think it could be bulbs, very odd more than 1 goes bad at same time, but I could be wrong.
One thing I'm sure...trailer lights are a pain in the .....

[pj4]

some new trailers have a connector near the lights, one for each side. check that first for power with a test light or voltage tester.you will know if the problem is before or after that spot. bad ground effect all the lights.wire code is yellow -left, green-right, brown-running light.most cases the white is ground

[Fathead]

Thanks for all your responses. It appears that PJ4 was correct. My shorelander trailor has to additional connectors (one for each side). They are located at the yoke of the trailor (where the tongue splits). One of the connectors to the failing side was disconnected. I stumbled onto it the other day at the landing.

Thanks again all