need help with 7pin trailer harness

[brodi3man]

Im looking for the wires to tap into for the back-up relay and battery charge relay.
I have the fuses and relays installed im just not sure where the wires go from there so i can finish running them back to the 7pin trailer harness.

I have a 2005 Expedition XLT which had the factory 4pin trailer wiring installed.
fuse panel is in passenger side kickpanel.

Thanks much for your help.

 

[ELVATO]

Yours didn't come with both 4 and 7 pin connectors?

For the reverse, you could use a relay, and have the reverse lights act as the trigger.

 

[brodi3man]

No it had a factory 4pin and the electric brake wire tucked away just behind it. It also had the brake controller harness under the dash. The fuse box is setup for reverse light relay and for battery charger relay. there are wires leading away from the terminal im just not sure where they go after that. I dont wanna untape the entire wire loom going back to the hitch if i dont have to.

I'd use the reverse light wire off the tail lights but i'd rather not put that extra load on that wire. Im pulling a small camper.

Brit

 

[ELVATO]

Oh, I thought you were going to use a relay running straight from the battery. You could tap into one of the reverse lights as the trigger for the relay, which wouldn't any significant extra load on the reverse light circuit you choose.

 

[juliet99]

Does the pin don't have the names where you need to connect the wire on your trailer? I have not yet try to repair my trailer because my trailer still in its good condition. I think it is better if you will read the manual of your trailer. Or just call a person who can know how to connect the wire.

 

[mtondreo]

Brodi-I'm sure you have this done by now. If not here are some notes I got from another forum (I think). I still have not gotten around to doing mine, butbhopefully it helps if you are not done yet. I have a tendency of copyingnstuff I may use and forgetting where I got it - so if this came from someone on here, Please take credit form your notes.

A little more detail:
What I did to convert 4-pin to 7-pin trailer connector on a 2004 Expedition:
Removed 4-pin connector from hitch (just slides out)
Cutoff 4-pin connector bracket from hitch (ground down two small welds)
Welded 7-pin connector bracket to hitch
Painted entire hitch black
Attached 7-pin connector to bracket on hitch
Cut and strip wire feeding 4-pin connector (Note: This step could be avoided as some 7-pin connectors have a 4-pin connector input) Just plug in, I preferred to splice the wires together.
Splice or attach the five wires to the 7-pin connector to the proper pins (Green, Yellow, White, Brown & Blue) Note: you may want to upgrade the white ground wire to 10 gauge (just like factory 7-pin)
Look under the drivers side rear door, you will find two wiring harnesses there
The smaller harness has an****Orange****wire going in one end of the harness but does not continue after.(pin12) This is the 12v lead
Splice into the wiring harness orange wire and wire back to the 7-pin connector. I used 12 Gauge wire and protected it with wire loom.
Note: The larger harness has a black/light green wire going in one end of the harness but does not continue after.(pin8) This is the reverse backup light wire if you want it. I did not so I did not wire.
I then tye wrapped all the wires up and out of the way being careful that the wire does not get caught up in the rear suspension or spare tire movement.
Remove fuse panel cover from front passenger foot area
Install standard****automotive****type 30-amp relay into slot R05
Install 30-amp maxi fuse into slot 106. I found a spare in slot 105
Replace fuse panel cover.
Connect brake controller wiring harness under the dash to your brake controller
Checked all 7-pins with a meter to be sure I wired all correctly.
That’s all I did and everything works great. I have got trailer brakes and switched 12volt power in my travel trailer now.

Parts list:
7 pin connector (I got one with both 7 pin and 4 pin connections)
7 pin mounting bracket
30amp standard automotive relay
30amp maxi fuse (there was a spare in my fuse block that I used)
12 gauge wire from pass floor connector to 7 pin (12v lead)
Wire loom to protect wire
Trailer brake controller adapter for Ford Vehicles
All parts are available from just about any automotive store.

I don’t recommend trying this unless you are familiar with wiring."
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2004 Expy Eddie Bauer 4x4 5.4L
1995 Jeep YJ 4x4 4.0L
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