trailer hitch wiring
Elder User
Joined: Jul 2004
Posts: 637
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From: Media, PA
I'm just taking a guess here. I'm assuming since you want to add the 7-pin plug, your Expedition does not have the trailer towing package, correct? I believe all Expeditions with the TTP come standard with the 7-pin plug. To add a plug can't be that difficult. As long as you have a schematic of the wiring under the rear bumper for the running lights, brake lights, turn signals, etc, you should be able to wire something up. Only thing you may have to do is run a power wire from the plug to the battery if you want to utilize the electric brake circuit or to charge the trailer brake battery through the plug. Like I said, I'm just taking a guess about all this. Someone else may have some additional info on how to do this.
Fleet Owner
Joined: Apr 2008
Posts: 24,318
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From: 0,0,1
What year? My 97 came with the factory 7-pin connector so I am assuming all of the wiring is back there. It just might be a case of swapping out your plug and pigtail for the 7-pin one. Does your pigtail run to the back left corner and plug into two connectors from the vehicle?
Senior User
Joined: Dec 2008
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Posting Guru
Joined: Aug 2007
Posts: 1,079
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From: Fort Wayne, IN
It's easy enough to get a hold of the connector. What he's asking is if it's plug and play in the back. And from what I know it is not. If u have the factory 4pin harness, you'll find under the bumper the 4 wires plus a tied up 5th blue wire. This is the blue wire that comes from the harness under your dash for the electronic brake controller. The rest of the wiring you'll have to do. You'll have to fuse and wire a line to the back for 12v to the plug yourself. Most people find this pretty simple. Just connect the wire to the battery, fuse it about 12" from the battery, then run the wire down, along the frame, to the back of the vehicle. But if you're not confident in your abilities, just take it to a truck shop or RV place. My local truck accessory place offered to run 4/5/6/7 quad mount bumper system wiring and all for 100$.
Postmaster
Joined: Oct 2006
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From: SE Texas
JL
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Senior User
Joined: Dec 2008
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It's easy enough to get a hold of the connector. What he's asking is if it's plug and play in the back. And from what I know it is not. If u have the factory 4pin harness, you'll find under the bumper the 4 wires plus a tied up 5th blue wire. This is the blue wire that comes from the harness under your dash for the electronic brake controller. The rest of the wiring you'll have to do. You'll have to fuse and wire a line to the back for 12v to the plug yourself. Most people find this pretty simple. Just connect the wire to the battery, fuse it about 12" from the battery, then run the wire down, along the frame, to the back of the vehicle. But if you're not confident in your abilities, just take it to a truck shop or RV place. My local truck accessory place offered to run 4/5/6/7 quad mount bumper system wiring and all for 100$.
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Posting Guru
Joined: Aug 2007
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From: Fort Wayne, IN
No it's not. If you want the live charger/12v line you have to run one from the battery to that harness to get that. The blue brake controller wire is probably already there if you had any non-standard duty packages on the truck. You may also wish to wire up the 7th pin to either aux power, or wire it to your backup lamps so your trailers reverse lamps will work.
Either way what you posted is *not* plug and play. If you did not get a 7pin from the factory you have to do some wiring. There is probably a Ford harness that would tie it in, but looking at my 04, the wires are not just laying there for you. The blue brake controller wire is tied up with the 4pin harness, but you still have to run the reverse and 12v aux lines to the rear harness. You can use these diagrams to see the differences.
Trailer Wiring Diagram For 4 Way, 5 Way, 6 Way and 7 Way circuits
Either way what you posted is *not* plug and play. If you did not get a 7pin from the factory you have to do some wiring. There is probably a Ford harness that would tie it in, but looking at my 04, the wires are not just laying there for you. The blue brake controller wire is tied up with the 4pin harness, but you still have to run the reverse and 12v aux lines to the rear harness. You can use these diagrams to see the differences.
Trailer Wiring Diagram For 4 Way, 5 Way, 6 Way and 7 Way circuits
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Postmaster
Joined: Oct 2006
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From: SE Texas
JL