Need help with trailer wiring

[cuban b]

I have a cheap trailer light kit from wal-mart with a flat 4 connector. It works fine when my vehicle's headlights are off, but won't do anything when they are on.

I'm horrible with electrical stuff (obviously) and any ideas would be appreciated.

Thanks

 

[Shawn]

Sounds like maybe a groud issue. Did you ground the trailer to the truck? If not, drive the trailer arround a bit to get the rust off of the hitch/ball receiver. Some times that helps.

 

[anvil]

The white wire is the ground. Make sure it's grounded to the trailer and on the truck side to the frame. Using the ball as a ground is unreliable. Ground problem are usually intermittent, I'd look elsewhere. You've linked your problem to the headlights. What do you have the brown wire (running/tail lights) connected to on the truck side?

 

[Shawn]

Using the ball as a ground is unreliable.

Maybe, but having toungh weigh of 150++lbs is a purty good connection source. I have never had a problem grounding that way.

 

[anvil]

Sometimes it works. It just depends on the amount of rust, dirt, grease and bouncing around. It's not too big of an issue unless you're using electric trailer brakes which he probably isn't with a 4 flat connector. In any case it's really not that hard to just wire it up right.

 

[cuban b]

The truck wiring is good. Other trailers work fine. I'll double check the ground. thanks for the help.

 

[gijohn40]

it sounds like someone used the brown as the ground wire instead of the white... thats a common mistake in electrical wiring of trailers

 

[notajeep]

I think that GIJOHN is right.
Side note------->> An easy way to check if a bad ground between the truck and the trailer is the problem, is to just use a set of jumper cables from the trailer frame to the truck frame.

 

[bobmed]

here's a diagram I've had for a while