Trailer back up lights

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Sep 2, 2017 | 07:47 AM

sealer700

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Joined: Jul 2006

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Trailer back up lights

Im trying to tie in some auxiliary back up light to my 7 way trailer harness and I don't seem to have any power to the plug for the backup portion. Box on new trailer plug side says center terminal is backup power. Is this correct and does the backup power portion have to be flashed in to the truck or should it just be on? 2013 f250 6.7 lariat crew has Trailer plug in bed and by hitch and neither works. They both work for lights and brakes, just no power for backup?

Sep 2, 2017 | 08:21 AM

lynnmor

More Turbo

Joined: Dec 2011

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Is there a 10 amp fuse in position 70?

Sep 4, 2017 | 07:30 AM

sealer700

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There is a fuse there. It was blown and i replaced it and still nothing. That was the first thing I checked!

Sep 4, 2017 | 08:09 AM

djousma

Logistics Pro

Joined: Mar 2005

Posts: 3,526

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From: West Michigan

Did the fuse blow again? A little detective work is necessary to determine if there is a short in your trucks wiring, or the trailer wiring would be my next move.

Sep 4, 2017 | 08:09 AM

Log Hog Kust'em

Tuned

Joined: Oct 2009

Posts: 417

Likes: 134

From: South Texas

I have reverse light on my trailer. All I had to do was plug in the trailer to my 7-pin. I have had problems with connections to the 7 pin at times. It seems the plug to wiring harness is finicky

Sep 4, 2017 | 05:41 PM

ruschejj

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Joined: Jan 2009

Posts: 6,521

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From: Greenwood, SC

I've always had to run a new wire from the trailer plug to the rear for back up lights.

On occasion I've seen other wires jumped together in the trailer plug, like my interior lights are tied into the running light circuit. May want to check the trailer wiring to see if there are circuits colliding with each other. If you have a back up circuit existing on your trailer the manufacturer could have done something strange like run it to ground or combine it with a stop or turn signal.

Sep 5, 2017 | 07:01 AM

sealer700

Thread Starter

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Joined: Jul 2006

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found problem. Jack hole that owned truck before me had put a 7 pin in bed side of truck and had wiring all f****d up. Works fine when wired right, go figure.

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Sep 7, 2017 | 10:05 PM

cangim

Postmaster

Joined: Nov 2003

Posts: 3,595

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From: Utah County, UT

Glad you found the issue, question though. Where do you have backup lights on your trailer? I keep thinking I'd like to add but haven't landed on what to light up