Baffled by trailer lights

parsleap

Seaman Apprentice
Joined
Feb 2, 2003
Messages
34
Maybe I'm not seeing something here, and hopefully this is an easy fix. Sure would appreciate some help.<br /><br />I replaced my boat traler lights today, as one had been busted. I didn't run the new wire all the way to the hitch hook-up, because it was still good. On the lights, I grounded them, and spliced brown and green and brown and yellow correctly. <br /><br />Everything on the lights works (flashers, turn signals, brake lights, regular lights) EXCEPT when I try to turn the lights AND hit the brake lights at the same time. Then everything goes off completely. I'm really at a loss here - I scrubbed the grounding areas with a wire brush to make sure I had good contact, but I'm wondering if this is something with the vehicle/trailer combo. I didn't actually hook up the ball hitch to the truck, but I did attach the chains so that the trailer and truck would be grounded together.<br /><br />Anybody got any thoughts on what is happening here? It's really got me scratching my head. Worked on trailers and lights plenty and never seen anything like this. Almost like a current limit switch, but these trailer lights aren't that sophisticated.<br /><br />Any and all help greatly appreciated!!<br />Thanks<br /><br />AP
 

tommays

Admiral
Joined
Jul 4, 2004
Messages
6,768
Re: Baffled by trailer lights

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<br /><br /><br />If BOTH ends of the plug are grounded corectly?? there is no need for the trailer to be connected to the car.<br /><br />IF it worked before ? A bad ground would be the most likely<br /><br />tommays
 

crab bait

Captain
Joined
Feb 5, 2002
Messages
3,831
Re: Baffled by trailer lights

GROUND GROUND GROUND..!! IT'S ALWAYS THE GROUND.. <br /><br />chains for a ground connection is a terrible ground..<br /><br />matter-o-fact.. i run a ground wire to my flat plug an ground it at the vehicle.. <br /><br />no trailer hitch ground at all..
 

PierBridge

Chief Petty Officer
Joined
Sep 3, 2004
Messages
625
Re: Baffled by trailer lights

That's the way to go for long term hassle free trailer light problems.
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: Baffled by trailer lights

Yep...start at the vehicle ground and work your way back. Once you have a good clean connection, paint it with something like liquid vinyl to keep the corrosion out.<br /><br />Like crabby said...lose the ball hitch/chain ground connection and connect the plug ground directly to the trailer.
 

parsleap

Seaman Apprentice
Joined
Feb 2, 2003
Messages
34
Re: Baffled by trailer lights

OK, I'll take a look today. I really appreciate the responses. Like I said, I used the existing 4-flat hook-up that was on the trailer, and it does have a white ground to the trailer itself at the front end (though nothing to the tow ehicle), and of course there are white grounds at each of the lights that I brushed and reconnected. I didn't mess with the front end ground, but I'll revisit it today.
 

Reel Poor

Vice Admiral
Joined
Jan 29, 2005
Messages
5,522
Re: Baffled by trailer lights

You must have a good ground between the vehicle and the trailer. That is where you will find your problem.
 
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