backup wire on trailer plug

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Mar 14, 2005 | 09:13 PM

medtech

Thread Starter

Freshman User

Joined: Dec 2004

Posts: 32

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From: Mass

backup wire on trailer plug

The backup wire doesn't work on my 7 pin trailer plug. I'm trying to hook up a backup light for when I'm plowing and have it easily removeable so I wired it into a 7 pin connector but the reverse wire does not have power. All other wires work (running light, stop, etc..) The truck is 2000 f350 extended cab, 5.4L, Auto. I checked a few fuses. Any other ideas?

Mar 14, 2005 | 09:33 PM

3BLADZ

Mountain Pass

Joined: Jan 2004

Posts: 133

Likes: 1

From: Illinois

I looked at doing this as well, I can't remember if the truck had anything actually hooked up to that wire. But what I did was to put a relay behind the tail lite powered off of the BU lites. Then, I plug in a trailer plug for power fom the trailer marker lites and run it thru the relay contacts so the aux backups only come on in reverse.

Mar 15, 2005 | 12:13 AM

wlihntr

Postmaster

Joined: Jan 2004

Posts: 4,758

Likes: 7

From: colorado

Quote:

Originally Posted by medtech

for the the back-up lights too work you have to put a relay in the forward position of the "trailer tow package relay box" it is right next to the under hood fuse/relay box, which is right in front of the master cyclinder (the box for the relay is towards the passenger side of the main under hood fuse/relay box,its about 1.5" x 4" , its black and probably has some black tape wrapped around it) the front position is the "trailer tow backup lamp relay" and the rear position is the "trailer tow battery charge relay"

Last edited by wlihntr; Mar 15, 2005 at 12:16 AM.

Mar 15, 2005 | 07:51 AM

3BLADZ

Mountain Pass

Joined: Jan 2004

Posts: 133

Likes: 1

From: Illinois

Thanks wlihntr, I might do that on my 450 for back up light.

Mar 16, 2005 | 05:27 PM

medtech

Thread Starter

Freshman User

Joined: Dec 2004

Posts: 32

Likes: 0

From: Mass

yup, checked the little box next to the fuse panel and sure enough, missing relay. Popped one in and taadaa, the backup circuit works. Thanks for the help! This site kicks butt!

Mar 17, 2005 | 12:05 AM

99f350sd

Lead Driver

Joined: May 2003

Posts: 9,303

Likes: 48

From: Lyndonville, Vermont

Ya your lucky mine doesn't have the socket for that relay but the wire is just below it in a connector. I have the lights in the bumper for plowing also.

Dick