Brand new LED trailer lights-- Driver's side diving me nuts

mike64

Lieutenant Junior Grade
Joined
Apr 10, 2008
Messages
1,042
I had problems last season with my old driver's side trailer light working intermittently. Figured the wiring was bad, because when I messed with the wires the light would come back on.

So I decided to get a brand new trailer light kit w/LED lights. New wires, new everything. Installed yesterday, and the driver side light was much dimmer than the other. I messed around with the ground wire that attaches to the light mounting post, and it came on as bright as the other! Both lights worked great! Yay! Problem solved.

Shoulda quit right there, but the license bracket that came with the light kit was flimsy plastic, so today I decided to put the old metal bracket back on. So I make the swap, and the driver light is not working at all.

I know the 3 rules of trailer light problems-- bad ground, etc. etc. The LED lights ground at the posts where they bolt on as well as the tongue, unlike the old lights, that only grounded at the tongue.

So I sand the post where the light bolts on even though it looked pretty clean, reconnected the ground wire, and that got the light back to lighting dimly. Then I sand down the connection at the ground wire at the tongue. When I touch the wire to the clean connection at the tongue, the light goes on bright! I think, problem solved...Yeah! But when I attach the wire to the bolt at the tongue the light isn't working at all again.

I continue to try to get a better ground connection but I can't get the light to go on at all anymore, until I give up for the day. so WTF?? This problem is driving me crazy. It's like some gremlin is screwing with me. Anybody got any ideas what I'm doing wrong???:confused:
 

Proselect

Petty Officer 1st Class
Joined
Aug 17, 2009
Messages
237
Re: Brand new LED trailer lights-- Driver's side diving me nuts

Is your white wire from the trailer plug grounded on the trailer anywhere? If not then you are grounding through the ball to the truck and I never liked that idea. If your lights are grounded only to the white wire directly through the plug then that is not your problem. If your lights are grounded to the trailer frame then you have to make sure your whole trailer is grounded really well to the white wire going through the connector.
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,853
Re: Brand new LED trailer lights-- Driver's side diving me nuts

Eliminate all ground connections to the frame by running a ground wire from the lights to the harness plug at the tow vehicle.
 

reelfishin

Captain
Joined
Mar 19, 2007
Messages
3,050
Re: Brand new LED trailer lights-- Driver's side diving me nuts

If your trailer is a tilt model or if the tongue is bolted in place, make sure that you either run a ground strap to the frame from the tongue or extend the white ground wire back to a point on the main frame. I normally run a separate ground wire back to the rear cross member to be safe, grounded right at the light mounting bolts.
 

mike64

Lieutenant Junior Grade
Joined
Apr 10, 2008
Messages
1,042
Re: Brand new LED trailer lights-- Driver's side diving me nuts

Running a wire from the ground at the lights to the ground at the tongue did the trick. Thanks guys.
 

mike64

Lieutenant Junior Grade
Joined
Apr 10, 2008
Messages
1,042
Re: Brand new LED trailer lights-- Driver's side diving me nuts

Update: I thought installing ground wires fixed the problem, but it came back again! So I tested all the wiring with a voltmeter, it all checked out.

Turned out to be a bad wiring harness on my Jeep. Didn't think that was the problem because I have another (land) trailer that never had any issues with the lights.
 

Viking...

Seaman
Joined
May 26, 2009
Messages
69
Re: Brand new LED trailer lights-- Driver's side diving me nuts

If I can add a tip, this is something that has worked very well for me.

I ground all my lights and negative wiring directly to the frame with a 1/8" stainless steel pop rivet.
Crimp an eye connector to the wire and insert the pop rivet.
Drill directly through the frame using a 1/8" drill bit.
Dip the pop rivet in grease before installing, and you should get several years of maintenance free grounding.

For lights that ground using the mounting bolts, I double up the nut and use a larger eye connection.
That way, if the mounting hole gets corroded or is painted, or just doesn't ground very well, the wire/rivet/eyelet does the job.

Regards,
Viking
 
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