Just installed all new lights and wiring, question on ground

[199675hpforce]

Ok my lights work if i connect a bare wire(sparks) from the vehicle to trailer or have it hooked up via the hitch. Should'nt lights work if i plug in harness (without hitching up trailer and truck).

 

[mudslinging79]

Re: Just installed all new lights and wiring, question on ground

did you use a ground wire from the harness to the trailer??

 

[199675hpforce]

Re: Just installed all new lights and wiring, question on ground

Yes i have two white wires running down each side trailer and all converge to the front harness white wire attached to trailer. Not only that all side markers are double grounded one through the bolt and white wire. Even new rear lights double grounded. The only items not replaced rear three light bar and brown wire. I cant seem to get the bolts out.

 

[mudslinging79]

Re: Just installed all new lights and wiring, question on ground

stupid question, is the other end of harnes, truck end grounded also??

 

[Moody Blue]

Re: Just installed all new lights and wiring, question on ground

You should have a separate WHITE wire coming from the trailer side of the plug. That WHITE wire must be physically attached to the trailer frame to provide a GND from the vehicle to the trailer frame.

 

[jay_merrill]

Re: Just installed all new lights and wiring, question on ground

If you have a chevy with a tow package, be careful - there may be two white wires in the bundle that you hook a connector up to. One is a ground and one is a hot. I forget the circuit involved, but it may be the high/center brake light for the vehicle.

 

[Moody Blue]

Re: Just installed all new lights and wiring, question on ground

Wow you all type much faster than me

You do not have a ground between the vehicle and trailer. Is the wire harness new or older? Using an ohmmeter, check for continuity between the trailer frame (clean bare metal) and the GND pin on the trailer connector (unplugged). Betting you have an open circuit somewhere in the GND wire from the connector.

What type of trailer connector do you have? Flat 4 pin, circular 7 pin?

 

[199675hpforce]

Re: Just installed all new lights and wiring, question on ground

Hi yes my newish truck harness is grounded underneath to the body, i dremel this area, new 1/4 self taping screw and locking washer. Then painted over the top with clear so no rust. Truck side is good! Now the trailer, i lost all lights last week when i tried to hook up. It blew my jeep crd fuse so it must have been a brown wire grounding out. I did find a rub on one of side lights brown wires not sure if this was the problem. Now the Update i decided to get all new lights and wiring at wally world and start from scratch. Lights will work if the trailer and vehcile are hitched. If i plug harness non hitched lights do not work. The right side like has a small amount of flicker thats it. So is there a leak somewhere? My test was done on Nissan frontier i have the jeep isnt availble. Im wondering if trailers dont have a way to ground unless your hitched up? Anyone verify this with 4pole? Doesnt make sense as my truck white wire is grounded id think this is all thats needed to make ground accross trailer side?

 

[199675hpforce]

humm got me thinking

humm got me thinking

so my problem must be the ground from the truck to the trailer and somewhere inbetween there's an issue. Or maybe the rear three tab light brown wire is leaking current into the frame and messing up the ground that i just installed. I did do a test with my omh meter and found small amount of voltage like 1.6 how i did the test is confusing my mind lol. The continuity test how would you check?

 

[redone4x4]

Re: Just installed all new lights and wiring, question on ground

You should have a separate WHITE wire coming from the trailer side of the plug. That WHITE wire must be physically attached to the trailer frame to provide a GND from the vehicle to the trailer frame.

ditto. this was the problem i had. Re-did the ground, mounted to the side of the tongue, did a little grinding on it and no more problems. Also, all my lights are grounded by themselves. But i would just re-do the white ground coming off the trailer side of the 4 flat harness. It should go from the harness straight to the frame/tongue.

 

[199675hpforce]

more information LOL

more information LOL

Ok just narrowed it down to my ground on the trucks harness. Get this i get no ground on the body? Even after dremeling the heck out metal. Must be a ground problem with my nissan pickup. If i attach a wire to say chrome bumper it works, more ground i make the brighter the light. Im going to checkout all my grounds(trailer) i installed with scotch locks ive seen those not click on all the way or not stick wire all the way down. Has anyone seen a truck without a ground to body? Is this some security feature with nissan.

 

[redone4x4]

Re: Just installed all new lights and wiring, question on ground

whats wrong with grounding it out to the bumper or the bumper mount/frame? that will work. then you know the truck and trailer are grounded out 100% seperately.

 

[cgd7777777]

Re: Just installed all new lights and wiring, question on ground

always ground the trailer
dont rely on the hitch

 

[redone4x4]

Re: Just installed all new lights and wiring, question on ground

always ground the trailer
dont rely on the hitch

the problem is with his truck now.....trailer is good.

 

[Moody Blue]

Re: Just installed all new lights and wiring, question on ground

The ground connection point for the truck side of the harness MUST be directly to the frame of the vehicle and NOT a body panel.

Get rid of ALL the scotchlock connectors. Those are the worst possible things you could use in this situation. Even when you get the problems worked out, the scotchlocks WILL fail in short order in an exterior exposed environment.

Just my 2 cents.