Help - Boat trailer lights problem??

[krats]

I am trying to figure out a problem with the running lights on a boat trailer. When I hook up the lights it blows the vehicle fuse for the left side tail light of the vehicle. But the brake lights and turn signals will still work on the vehicle and trailer. I cannot see any visible flaws in the wiring on the trailer that is exsposed at connections. I think that my next step expose any of the connections that I can get to and check them out.

Since it just blows the drivers side fuse does that mean the problem exists on the drivers side of the trailer also?

Can any one give me any tips on what the problem may be?

Thanks.

[iffy]

Sounds like you have a corroded, broken, or not hooked up ground wire from the vehicle side of the connector back to the vehicle. Was this an add on or a factory wiring? GMC vehicles require the white(ground)wire to be grounded to the frame.

[Jeremy airjer W]

my best guess is that there is a short to ground somewhere on the brown wire of the trailer harness. Are you using a four flat and or a 7 way adapter?

The tail lights are probably only running of the driver side of the vehicle thus only blowing that fuse. The other lights working properly would reasonable eliminate a ground being the issue.

[krats]

iffy,

It is my buddy's trailer and it blew the fuse in my GMC truck first then we hooked it up to his Dodge mini-van and it blew the fuse on that. So that makes me think it is the trailer.

Thanks

[krats]

airjer,

This is a Ranger trailer, and the thing has conduit running full length of the trailer on both sides with a few gaps in it like were the marker lights are located.

The trailer plug is a 4 prong but it has 5 wires comming out of it. 1-green, 1-green w/brown stripe, 1-yellow, 1-yellow w/brown stripe, and 1-white(ground). They have the type of wire that is 2in1 going to each tail light, green-green w/brown down one side, and yellow-yellow w/brown going down the other side.

When it blows the fuse none of the running or marker lights work on the trailer, but the signal and brake light do still work.

The reason I know that it blows the driver side fuse is that the dodge van we hooked it up to has the fuses marked in the panel that way, but on my truck it only had one fuse for the marker/tail lights. I just thought that by chance maybe the left side had something to do with it. It still may and I will take a look at it on Friday.

Thanks for the help guys.

If anyone else has any ideas what to look for please reply.

[Jeremy airjer W]

The wires with the brown stripes are where you need to focus. I would imagine that these two wires end up at the same terminal on the plug. If you wanted to be really crude you could cut those two wires (leaving enough room to splice them back together of course) and then hook them up one at a time to see what side of the trailer is blowing the fuse. I would probably reserve this for a last case sceneario if all else fails.

The plastic looms usually have a slit that runs the length of it. If this is the case than you should be able to remove the wires without much trouble to inspect.

The other lights work because the trailer lights essentially work off three seperate circuits. Brake, Turn, Tail lights. Any one of these can blow a fuse and the other two will continue to function.

Good luck! Let us know what you find.

[krats]

Well I figured it out...I first pull the wires one side at a time and everything looked good. I put it all back then I knew that I needed to start looking at the lights themselves. I thought for awhile and remember that I have never seen the light bar with the three little marker lights on the back of the trailer work. So I disconnected the light bar, hooked up the truck, and "SHAZAM" everything else came on. I ran to Gander picked up a new light bar and now all is good. I wish I would have checked the light first, but I guess this kind of stuff is just trial and error when it comes to fixing trailer lights.

I will just chalk it up to experience.

Thanks for the advice guys.