2007 Expedition trailer wiring

[chevy24d]

Originally posted by chuck s
If you have the towing package the wire is already there.

The center pole of the 7-pole connector on the rear bumper is backup lights -- technically that pole is "undefined" or "auxillary" but Ford connects it to the backup light circuit. Was like this on my Explorer too....
-- Chuck

I do not have the towing package but will be adding the larger tranny cooler and larger rad. soon.

So does this mean that the wire for the back-up lights is still accessible in the rear bumper or were you only referring to vehicles with the trailer package?

Thanks again for your help!

Mark

ps - did'nt mean to hijack JD but it seams we are in the same boat...

 

[bobthegod]

This from another Expi owner and an RV'er. Forget the backup lights and battery charger line. Use the money to purchase a nice little Honda generator.....this will power all your lights AND charge your battery(ies if you have two). The new generators (2000 watts) are VERY quiet and efficient. If your batteries run down you'll need to recharge them somehow and hooking up the car everytime gets OLD fast. Onan makes a nice add on generator thats called a JUICEBOX that is mounted to the rear of trailer......goes on and off easily so you can use it at home too. But any small generator can be mounted to you rear bumper (of the trailer) and you can run it while in motion also...to charge batteries run a fridge while traveling etc. Stick with the Prodigy brake controller also it's the best one going. I installed one on an exploder and it works like a charm......very smooth and easy to program on the fly. I wouldn't worry alot about trans coolers as you didn't say how heavy the trailer is, tell us more about it and where you'll be towing....Hills or flats. I also suggest looking at your GCVW Gross Combined Vehicle Weight listed in your owners manual. DO NOT go over the limit....voids warranty. You should be able to handle a 5000 lb trailer easily. For more tow rating info go Motorhome.com or trailerlife.com as they have a lot of tow ratings for new SUV's.

 

[chuck s]

To my knowledge neither the trailer battery charge (or Aux) wire nor backup light wire is at the rear bumper unless you have the HD Towing package.

But they're two wires easily added and one is really there anyway with the backup lights on the vehicle.

Trailer battery charge is no more than a trickle charge.

-- Chuck

 

[tk1971]

OK. I'm getting ready to do this, so with everyone's help here (with drawings, pictures, etc), this is what I found with my multimeter and electronic wire tracer:
1) Empty battery charge fuse is live
2) Empty fuse has a connection to the fused output
3) Empty fuse has an ignition 12V and ground
4) The remaining switched relay output goes to the Orange (10ga?) wire to the harness connector inside the engine compartment on the driver's side near the firewall.
5) The other side of the connector does not have a pin and corresponding orange 10ga wire going to the back of the vehicle.

So, with a 30amp fuse and a Radio Shack 275-226 relay (with the tab sawed off), I can get a fused/switched 30amp 12V supply to the harness near the firewall. All I gotta do next is cut the orange wire off the harness and buy some 10ga stranded exterior rated wiring (Underground rated romex?) and put it in it's own wiring loom, then zip tie it to the existing wiring loom going to the back of the vehicle. Tap the reverse light for the backup, and then I'm all set. I think I'll get one of these as well from etrailer: Adapter 4 Pole to 7 Pole & 4 Pole, OEM Style

tk

 

[chevy24d]

Don't forget to take pics for us...

 

[AvroAero]

Good luck!

 

[tk1971]

OK, I got as far as putting together the wiring before it started to get dark and rain.

Here is how the harness looks like (next to the maser cyclinder):

The harness is disconnected and the two wires needed have been cut (as seen in the picture).

Here is female end of the harness. The 12V 30A connection is shown:

Here is the Reverse connection:

So far I soldered the 10ga and 14ga wires to the 12v/30a and the Reverse/15a (connected to fuse #63) wires that were cut off of the harness. I put 2 flexible wiring looms on the total length of the wires and routed the wiring to the back of the vehicle following the original loom for the original hitch wiring. I just zip-tied the loom to the other loom at all the anchoring places. The original loom is pretty well sealed up, but I didn't feel like wrapping 8 rolls of electrcal tape around this loom, but I think it should be fine.

I got the wiring from Home Depot. 10ga and 14ga stranded service entrance wiring ($16).

Got me a Hoppy 47185 4-pole flat to 7-pole + 4-pole adapter, so it's as plug n' play as it can be. I now have an idea how to secure the new tow adapter (which has both 4-pole and 7-pole) to the hitch. The existing flat-4 connector is held in place by a metal ear welded onto the hitch. This ear has just enough metal for me to drill 2 holes in it. I can then use an angle to secure the Hoppy connector.

I'll have pictures of the final part when I get to it.

tk

 

[chuck s]

Are you running the trailer battery tow and backup lights thru relays?

Without a battery charge relay you can drain your starting battery when stopped if the trailer is using a lot of 12v amps.

The photos I posted near the top of the thread show where the battery charge relay and fuse go.

The diagrams show the box lay out in schmatic form.

-- Chuck

 

[tk1971]

Chuck,

It was your photos and correspondng diagrams that inspired me to check the stock relay/fuse box.

I will be using the stock battery charge relay and fuse. The wiring and the fuse box is the same at this point. The only differnt wiring is the harness connecting to the fuse box harness going to the back of the vehicle, which is missing the pins and corresponding wiring, so I had to run new wirng for the charge and backup.

I'll be using a Radio Shack 275-226 relay which fits the stock relay slot. I'm also tapping the 12V once the 7-pin connector is installed for backup lights.

tk

Thanks..

tk

 

[chuck s]

Looking good to me!

-- Chuck

 

[tk1971]

OK, the weather cooperated for a couple of hours today.

This is the stock 4-pin connector bracket on the hitch. I drilled 2 holes in it and painted it with Rustoleum to get it ready for the stainless steel bracket.

This is the 304 stainless steel bracket I'm making to mount the 7-pin Hoppy adapter:

It's almost done. The 4-pin Ford wire connects to the Hoppy connector. I still need to solder the remaining wires, put them in a loom and secure the loom so that it looks stock. But here is the Hoppy installed on my homemade bracket. If nothing else, I can tow my box trailer since the Hoppy has 4-Pin and 7-Pin connections.

The weekend's winding down. I tied up all the wiring and will finish this hopefully next weekend.

tk

 

[chevy24d]

Nice job TK - Thanks for the pics - they will help me!

 

[chevy24d]

TK - Can I ask why did'nt you just drill vertically (under the hitch) and mount the provided angle bracket to the bottom of the hitch?

 

[tk1971]

In order to keep the Class IV rating on the hitch, it is my understanding that it is "bad" to drill holes in it. But the original bracket for the 4-flat plug is welded onto the hitch and not really part of anything structurally important. That's why etrailer.com has all those 7-pin adapter brackets that either zip tie or tied to the hitch instead of being drilled into it.

tk

 

[chevy24d]

Wow - and I thought I was **** - I might do the same Although, I doubt (2) 1/4-20 tapped holes will really alter the strength of the hitch. I will have to think about this now.... Thanks -Mark

 

[trdragons44]

any body got any ideas for mine?

i don't wanting it hanging to low.

 

[tk1971]

I would either use this:

http://www.etrailer.com/pc-BRACKET~18136.htm

or this:

http://www.etrailer.com/pc-BRACKET~18156.htm

This is assuming 2 1/4" tubing, they have one for 3" tubing as well.

tk

 

[chevy24d]

TK and TR - I made a bracket picking up the opening in the stock 4-way mounting bracket and even eliminated any drilling. I have attached the link.

http://s254.photobucket.com/albums/hh92/boatrboy/Expedition - 2007/?action=view&current=IMG_1709.jpg

TK - can you elaborate on the reason for cutting the wires and where do they go on each side of he connector?

Thanks

 

[tk1971]

chevy, that's some fancy machining. Nice bracket.

As for the wiring, the only wiring I had to cut was under the hood on the stock harness connector (from the fuse box side). That's only to route the 12V and the reverse to the back.

At the back of the vechicle: The 4 to 7/4 pin adapter has a flat 4 connector that connects to the stock 4 pin harness from the Expy. The electronic brake wire is already there, tucked away on the harness. The e-brake, relayed/fused 12V and reverse wires need to be connected to the connectors on the new 7 pin. I didn't cut any of the stock wires.

Here is how it now looks like:

I had to use 2 wiring looms, so along with the stock one, that's 3 total. The original Ford harness to 7pin connector was zipp tied and tucked up into the bumper skin above the hitch. All wiring looms were tied together with zipp ties.

Hope this helps. Now I gotta go and get the Radiator/Tranny-cooler.

tk

 

[tk1971]

One more thing for anyone wanting to do this, but didn't go through the entire thread. The non-HD tow Expies have the same fuse box under the hood. Putting a 30amp fuse and relay in place will get a fused/relay-controlled 12V to the hitch wiring harness connector up to the engine compartment. You will have to run a 10 gauge wire to the back of the vehicle to get the trailer charging 12V back there.

There is also a 15amp fused reverse 12V at the fuse box that ends in the engine compartment harness. There really is no need to pull this one, as you can get a reverse 12V by tapping one of the reverse lights at the back of the vehicle. But since I was pulling the 12V, putting another wire in the flexible wiring loom is really no work at all.

tk