Help Needed Trailer Wiring Trouble

JRJ04

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Well I was pulling a trailer this weekend and noticed i had no tail lights. I have both blinkers and brakes...but no tail lights. I was only using the 4pin connector. How can I test to see whats bad? I pulled off the entire wire harness that connects up near the spare tire and looked everything over and reconnected. Still had the same problem. Can I just replace that entire harness? Tried finding it online and didnt have any luck.

Any suggestions?

On edit...I know its not the trailer cause I hooked it up to another vehicle and everything worked fine.
 
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BIG JOE

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Well I was pulling a trailer this weekend and noticed i had no tail lights. I have both blinkers and brakes...but no tail lights. I was only using the 4pin connector. How can I test to see whats bad? I pulled off the entire wire harness that connects up near the spare tire and looked everything over and reconnected. Still had the same problem. Can I just replace that entire harness? Tried finding it online and didnt have any luck.

Any suggestions?

On edit...I know its not the trailer cause I hooked it up to another vehicle and everything worked fine.

For starters..Use a test light and see if you have Brake light power at the 4 pin connector plug pin. Those 4 pin plugs are known for getting corroded JR.
 

jestersv

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LOCATE WIRES BY FUNCTION ONLY (from hoppys web site)
White Wire . . . Attach to good ground
Yellow Wire . . . Attach to left turn
Green Wire . . . Attach to right turn
Brown Wire . . . Attach to the taillight
if both brake lights work you can assume that both yellow and green circiuts are ok you can also assume that ground is good that leaves just the brown wire left. If you run into the tail lights work but flash with the blinkers or go away with the brakes it is usually a ground prob. so I would start at the back of the i assume truck if there is no power check fuse, for superdutys there is a fuse for trailer connections under hood, check the owners manual for which one.
 

Tail_Gunner

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Check your fuses in the power box under the hood. There are trailer light specific fuses for
Left Turn/Stop
Right Turn/Stop
Tail/Marker lights
 

BIG JOE

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Check your fuses in the power box under the hood. There are trailer light specific fuses for
Left Turn/Stop
Right Turn/Stop
Tail/Marker lights

What TG sez.

Then, once you know you have good trailer specific power to the bumper connection(s)... get yerself a 7 pin adapter plug, that converts to a 4 pin. Keep it In the truck, Outa the weather. Makes pulling most Any 4 pin trailer a breeze. Lighting-wize.

And.. If you do a good bit of towing ? Bargman, and others, make neat little plug-in LED testers.. At least yul know if the Gremlin is yours, or the trailer's. I have found them to be a Very handy tool, not only for me.... but helping others too.. Cequent

Joe
 
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mille-ryan

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Funny story exact thing happened to me this past week.I knowticed the the pin as corroded bad on the tail light prong truck side.I got one of them adapters for he round prob jut go that route.
 

JRJ04

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Problem Solved!

Bad fuse. Pulled it, replaced it...all is good! i had no idea there were fuses for the trailer wiring?:dunno

Thanks for your help!:sweet
 

DaveBen

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After seeing the junk that people pull, I would hope that Ford was smart enough to fuse the trailer connections. Can you imagine pulling a trailer on fire, due to an electrical fire?

Dave
 

BIG JOE

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After seeing the junk that people pull, I would hope that Ford was smart enough to fuse the trailer connections. Can you imagine pulling a trailer on fire, due to an electrical fire?

Dave

And aint that the truth !

Speaking of fuses ? Found fuses a AutoZone that have a mini LED that glows.. when the fuse blows ;tu

Handy when things suddenly don't work.

Joe
 

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