Trailer wiring ???

[FED 387]

Bought a used enclosed trailer---all the lights work HOWEVER when you turn on the flashers or turn signals not only do the taillights work on the trailer although not real brite BUT the clearance lights on the trailer all flash and the Stop lite on the cab flashes too---BOTH turn lites on the truck flash but depending whether you are signaling left or right whichever way you signal that lite will be brighter than the other taillite but both are flashing---Disconnect the trailer and the truck is OK--put a new 7 prong plug on the trailer cuz the old one was a little scuzzy that did not help--- The guy I bought the trailler from had just installed ALL NEW Led clearance lites and 2 NEW regular (not LED)stop/turn lites---Anybody got any ideas??? I think I have a pinched wire some where but do not want to tear the whole interior out to find it---He also put new wood on the ramp door but I have no idea if he rewired it while he had that open- Suggestions gratefully accepted--Thanx Comp 387

[art leong]

I had a problem similar to that. They had one of the brake lights wired to the running lights.
When you put on the lights the brakes locked up.
Trailer wiring on trailers built up north can be a real problem to get to, because they are all enclosed.

[krugracing12]

Add a ground wire from the truck frame to the trailer frame and the trailer frame to rear door frame. We have several older haulmarks that had the same problem and that cured it.

Bill

[FED 387]

OK guys Thanx will look into both ideas---anybody else got any more ideas??? Thanx FED387

[Wayne Ewing]

Sounds to me like you could have a bad ground and some wires crossed up in your plug. Had some of the same problems on my Goldrush this summer and spent 2 days trying to figure it out. Are your trailer wires color coded? If I remember corectly the yellow is left turn, the green is right turn the black is taillights, the white is ground the brown is running lights, the red is to charge the trailer battery and the blue is the trailer lbrakes. The ground wire (white) has to go into the center post of the plug. Hope this helps some.

[FED 387]

Wayne just double checked the wiring on the PLUG---the colored wires are where they are supposed to be---the center wire position on the trailer plug has no wire attached to it --never did days its for backup lites-no wire in the harness is available to attach to it---I do not understand how you run a ground wire from the truck to the trailer when I think going thru the hitch ball would work but if that is not the case how do you ground the trailer to the truck or the trailer door to the trailer frame???( hinges on the trailer door metal on metal not a good enough ground???)---I'm game talk to me this is exasperating spent all day Sun futzing with this bout ready to completely rewire the frigging trailer get it over with BUT I dont wanna do that hafta pull the ceiling down etc.--- Keep those ideas coming ---Comp 387

[Michael Pliska]

Just try temporarily hooking a jumper cable from the truck frame to the trailer frame, to see if grounding is the issue.

[GTX JOHN]

I agree... sounds like a ground wire problem for sure. The LEDS
are not as fussy as conventional bulbs. When the ground is bad my trailer do a lot of backfeeding and funny stuff.

[Shawn Blair]

It's more than likely a grounding issue from truck to trailer. This has happened to me before, but as soon as i started driving the ball and hitch made a good ground and it worked fine. Good luck!

Shawn

[Mark Ruset]

Make sure that your brake light bulbs are indexed properly. I have seen where it is possible to install the bulbs 180 degrees out and cause this condition.