Just because you have the brown connector under the dash DOES NOT mean you have seven wires under the van. I have the connector under the dash, I do not have seven wires under my van. All relays and fuses are in place but the three pin connector is not there under the van. I only have the four pin connector. Believe me, I'm an electronics technician and I have the schematics, I have spent a good hour under the van tracing wires and looking for the three wire connector. Like I said in my last post, the schematics say "some vans equipped" next to the three pin connector.

 

Yes, you do have the seven wires. The four flat only goes about 2 feet to a connector under the rear of the van. Next to that connector is another connector. The seven way from Ford comes with two connections. One plugs into where the four way was, the other plugs into the 3 pin connector next to it. They are located just behind the driver side rear tire. Not under the hood. All the towings packages came this way. I was delighted to find it that way one day when I went to wire up the van.

 

maples01 and al-e.-gator,

Maples mentioned the length of the harness being different due to his van being extende. The way they do it is to use the same part number wiring harness on both length vans. The short van has a loop in the harness and the excess is stuffed into the frame rail. The longer van will have that slack that formed the loop straightened out. The harness should play out to about the same length relative to the bumper on either length van.

Get under the van on the driver's side and look inside the frame rail for a wiring harness that is 3/4" to 1" in diameter. It works like Adventure and I said in previous post. The harness ends about two feet from the bumper and terminates into two plugs. One id three pin and the other is four. This is where the final pigtail that completes the circuit out to the bumper plug attaches.

I haven't seen the wiring under a van that only has a four pin plug at the bumper, but I would be surprised if they made a special harness to feed that setup after seeing the way they loop the harness for the two van lengths. I think that a van that has a four pin bumper plug will have the three pin connecter, unused, about two feet forward of the bumper, next to where the four pin pigtail connects.

Gene

 

I hope to get it located, gotta find where I put my controller and 7 pin, I boxed them up when I moved, now I've lost them.

 

Ok, just to clarify for everyone. My 04 E350 (bought used) did not come with a hitch or a four wire pigtail at the bumper. It did come with a brake controller connector under the dash and all relays and fuses related to towing with electric brakes and trailer battery charge installed in the fuse/relay box under the hood. Under my van behind the driver's side rear axle I have one four wire connector where I spliced in my four wire pigtail to the bumper (didn't want to pay my dealer $80 for the factory part). I do not have a three wire connector anywhere near it. I have the factory electrical manual and factory maintenance and repair manuals volumes 1 and 2. The electrical manual has a drawing of the the connectors needed for towing. In the picture it shows the four wire connector and the three wire connector which has a white wire going directly to ground on the frame rail within inches of the four wire connector. There is a statement that not all vans have this connector. Here is a link to a simular picture without the note, https://www.fleet.ford.com/truckbbas/non-html/2004/bb_pdf/183-184.pdf. I know exactly what I am looking for and exactly where it is supposed to be but it is not there. So, if your van did not come with the towing package (hitch and seven pin connector installed) you may not have all seven pins at the rear axle. You will have the four pin connector which is round and attached to the frame rail. I have a pinout of this I can post later if anyone needs it. Once I take the time to find where I have to wire in the other two connections (remember, one of the three is a ground) for brake control and trailer battery (maybe at the fuse/relay block) I'll post the instructions here.

 

gator,

Thanks for the info - and schematic. I tried looking on that site for something I was interested in and finally gave up. Ford offers "Daytime Running Lights" as an option on new vehicles. I was wondering if it was simply a relay that I could plug into the power panel, but so far I haven't been able to come up with anything...

 

al-e.gator,

What seems strange to me about your van is that the towing package relays and fuses are all in place in the absence of the 3 pin connector. It's easy to see why the bean counters would eliminate the three extra lengths of wire and the extra plug. Thirty feet of wire and a plug add up to a pretty good savings over the production run of a few hundres thousand vehicles, but then to turn around and do just the opposite when it comes to the relays and fuses, which cost as much or more than the wire doesn't make sense to me. Also considering that most people just get a plastic bag with the relays in the glove compartment when they order the towing package. My relays were installed, but the fuses were not.

For the others that are looking to see if they have the wiring harness in place on there van, I miss spoke on the location of the end of the harness where, in my case, there are two plugs. I said before that the plugs are two feet from the bumper. Actually, there is a hole in the last cross member of the chassis that the wiring harness comes through on the drivers side rear less than a foot from the bumper. The two plugs just barely stick through this hole. It is at this point that the pig tail that is connected to the factory seven pin bumper plug ( if so equiped) would plug in and the white wire from that pig tail is grounded by means of a screw into the chassis.

gator, if you have a chance to take a look at your factory schematic and see how the ground for the instrument cluster is implemented, I would appriciate it. I need to know if it is in the multi pin connector ( assuming there is one) or a seperate ground lead to the body under the dash from a star ground type arragement or something else. I have a thred concerning my oil pressure gauge and need to know what I'm looking for when I take the dash apart.

Thanks,

Gene

 

Gene,
Yeah, I can't understand why I have alll the relays and fuses in place but no wires and to top it off there is only two wires to run. The third one is a ground to the frame so they only need a few inches for it. I have confirmed the relays and fuses twice because I spent so much time under the van before I got the schematic thinking " I have the relays and fuses, the wire has to be here." I'll try to look up the ground for you, there are 10 years between model years and my dash is different but I don't think they would change the ground very much.

 

Thank you sir. That would be a big help. Ford doesn't support the '94 model year any more on their on line data base and I just have the Haynes manua,l which borders on useless. It doesn't even cover the correct fuel injection system for my model, among other things.

At the risk of irratating you, when I looked under my van this morning I noticed that the two plugs on the harness just barely stick through the hole in the chassis cross member. The harness splits just in front of the cross member into a wye. So it might be possible that the other plug is hiding on the front side of the cross meber and only the side of the wye with the 4 pin plug got pushed through the hole. I know you've looked and that probably isn't the case but it would be a nice suprise to find it hidding in there somewhere.

Gene

 

No, I'm not irritated, I wish it was as simple as that. My harness dosn't come out of any holes. It just runs down the side of the frame rail and is held in place with little plastic plugs that are bound to the harness. At this point, if the cable is hidden, it is almost easier to just solder wires to the bottom of the relay tray and run them to the back than to spend anymore time crawling around under the van.

 

Mine runs in the main frame channel on the left side and ends up going through a hole in the last cross frame cross member. It's at that point that the harness wyes for the two plugs. It is possible for one leg of the wye to end up on either side of the hole if they were not being used.

Gene

 

Longtime coming, but I finally installed my brakesmart brakecontroller in my 04 E350. I had posted earlier that I had the brake control wires, relays and fuses but did no have the brake control and battery charge wires at the back. Well after spending a couple of hours with the factory electrical manual I found that the first place to look for these wires is Connector 110, pins 1 (brake) and 9 (battery). Connector 110 is the major harness connector just under the drivers area of the van. I got under the van and took connector 110 apart and found out that the wires in question were present in the female (towards the front) connector but not in the male (towards the rear) connector. The places for pins 1 and 9 are blanked off. Here's what I did to hook mine up. I bought 25 feet each of blue (brake) and orange (battery) 12 gauge wire and ran them both from the rear up to connector 110. I punched out the blanks in the male connector. This exposed the orange rubber pin holder. Then, I pulled the red pin lock for the first row of pins out. I pushed the 12 ga wires into their respective holes and out the other side, stripped them 1/4" and tinned the ends with solder. I pushed the wires back into the connector until the tinned wires stuck up even with the other pins and put the pin lock back in. A tinned 12 ga wire is almost the same size as the factory pins so at this point I just put the connector back together and plugged it in. Everything is working great so far.

 

al_e._gator,

Good deal! Your description of what you had to do makes me feel very lucky indeed that my used '03 had the factory-installed heavy-duty tow package!

Will you be doing any additional "waterproofing" to the connector you dis/reassembled?

DadVan

 

No additonal waterproofing is necessary. The wires I added have exactly the same waterproofing as the factory wires. The connector has an orange rubber seal that is full of holes. the holes are closed to moisture when nothing is in them and the rubber seals around wires you push through the holes. The connector only has about 75% of the avialable holes used from the factory. The work itself wasn't bad, it's the research that was the real pain.

BTW the only part of the "heavy duty tow package" I didn't already have (besides the readily available seven pin connector and hitch) was those two wires. Doesn't make much sense does it?

 

Hey Al_e._gator! My 2004 E350 has the same issue as yours! C110 is the end of the line for brake, battery and backup lights. I spent a nice afternoon under the beast. I am still wondering what kind of wire and where you ran it. My 92 E150 had an added battery wire to the back for a boat winch(in service when I bought it). It slowly failed running the battery down. Finally one day is was a good short to ground. My point is The extra wires need to be safely installed for the next 200,000 miles. So....please share your secrets! thanks!