Miswired hitch plug?
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Senior User
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Miswired hitch plug?
I have a 1980 Ford Bronco. It came with a hitch and a plug. The plug is the standard flat plug with four wires leading from it. When I hooked it to my trailer all the lights worked except that when I press on the brake, the trailer lights go off. Upon investigating. I saw that the white wire from the plug on the truck was dead-ended; it was not connected to anything--just some electrical tape wrapped around it. Only three wires looked to be wired into the truck wiring--a green, a brown and a yellow.
On my '95 Dodge van, the white wire is connected to something in the van wiring. All lights on the trailer work when the trailer is connected to the van.
What gives? Where should the white wire be connected into the Bronco wiring?
On my '95 Dodge van, the white wire is connected to something in the van wiring. All lights on the trailer work when the trailer is connected to the van.
What gives? Where should the white wire be connected into the Bronco wiring?
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Joined: Aug 1999
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From: Bel Air USA
Like Dealford said the white wire is the ground. I've seen it not hooked up several times. I always hook it up to ground. Most people depend on the hitch connection for ground. If you were checking the trailer lights out without the trailer hitched at the time, that could be your problem.
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I did check with the trailer hitched. I even took the nconnected white wire and connected it to the hitch and it did not help.
The white wire on the trailer-side plug is grounded to the trailer frame. I even disconncted it to see if that woudl help but it did not.
This has me really stumped. Any suggestions? If I don't get it fixed with my luck I will get a ticket.
The white wire on the trailer-side plug is grounded to the trailer frame. I even disconncted it to see if that woudl help but it did not.
This has me really stumped. Any suggestions? If I don't get it fixed with my luck I will get a ticket.
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From: I live in a warehouse in
Not to hijack the thread, but would the color coding on a '70 CS be the same in the camper yoke as far as the lights on a trailer? (Yoke comes up behind cab). I know that there are more wires in there, but I just need to hook up my old boat trailer so I don't get a ticket either. Thanks.
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Joined: Mar 2003
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From: Sarnia, Ontario, CANADA!
Originally Posted by tombob
? Where should the white wire be connected into the Bronco wiring?
-Matt
Cargo Master
Joined: Aug 2003
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From: Belleville, Ontario
Originally Posted by Knight70F250
Not to hijack the thread, but would the color coding on a '70 CS be the same in the camper yoke as far as the lights on a trailer? (Yoke comes up behind cab). I know that there are more wires in there, but I just need to hook up my old boat trailer so I don't get a ticket either. Thanks.
Is your trailer plug 4 or 7 pins? You could build an adapter using the 7 pin male to plug into the truck(if you have the 7 pin female system on the truck now) and only run 4 wires from it-green=right, yellow=left, brown=running & white=ground. Whatever plug the trailer has on it, buy the other half for the truck & hook it up accordingly.
Have you checked the colour coding of the wires on the trailor? You can use your truck battery and 2 jumper leads to light up the lights.
As far as the ground wire issue goes, bolt both the truck half and the trailor half ground wires to their respective frame. Make sure that the point where you attach the ground lead is CLEAN & free of rust. Use lots of dielectric grease/silicone to seal it up good.
AL.
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From: Texas
Have you checked the wire on the truck side? Disconnect the 4-wire connector and get you a 12V test light. Have some one turn the running lights on, you should show power on the brown terminal. Now check you yellow and green, which are the turn signals. Now hit the brakes. The yellow and green also serve as the brake. Check the truck first and see if you get anywhere. Also, have you check the lamps in the trailer, maybe out?
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From: I live in a warehouse in
Thanks for replies. I have a seven pin hookup on truck. The mate went with the camper when I junked it (they wouldn't let me have it). I guess the smart thing to do would be to get a new matching set and just hook the four wires from the trailer into their correct slots, and the seven from the truck into theirs and all should work fine. Colors on truck are same as mentioned plus some others. Wires on trailer are old and painted over, but can easily be traced from fixture to hitch so I don't see any problems. I'll just splice new color correct wires onto trailer and that will be that. Thanks again. Guess I should have posted here in the first place.