Hello,
I recently purchased a 2008 E350 SD and plan to pull my camper with it, which requires a 7 pin plug. The van has a flat 4 harness installed, but apparently doesn't have the "towing package" option. I purchased a 7 pin pigtail from a Ford dealer, but there is only a connection for the 4 pin portion and doesn't have a connector for the other lines (12v charge, reverse lights and trailer brakes) The van does have the wiring plug under the dash for a brake controller, but I'm not sure where those wires terminate. What is required to wire this like the factory would of done it?
I checked the Power Distribution Box and it has the relays installed for the tailer backup lamps and trailer running lamps, but not for the trailer battery charge.
I also noticed that there is a dead-ended 4 pin plug under the hood on the firewall on the drivers side. This connector matches the plug that I need at the rear of the van to hook up the 7 pin pigtail. I'm not sure if it's related to the trailer wiring, but I would guess that it might.

Thanks for any help!

Jack
Fort Loramie, Ohio
Econoline owner since 1977. 1976 E150, 84 E150, 92 E150, 99 E150, 2008 E350.

 

Big ol post follows:

For some reason, my 2008 service manual volume refuses to load. Yippie.

2006 should be substantially similar (if not identical, ford is incredibly lazy!)


If the connector (C422) isnt located up in the frame rail (in the first image) then your van wasnt given the class II towing harness. You will have to go up to connector 110 (under the driver) and run the required wires from there to the back of the van. Fun on a bun. Images attached. If you are not comfortable doing this, then most decent tow shops should be able to pull it off.

C422 Location


C110 Location

 

Thanks much for the information. I took apart the connector (C110 in the diagram above) and found that three of the four wires on the outside corners don't pass through to the wire harness that leads to the back of the van. (blue for brakes, orange for power, black/purple for backup lights) The fourth corner is the white (ground) wire which passes through. I cut the wires just above the connector and spliced to them for the run back to the trailer connector. Since the relay isn't in place for the power line, I'll have to pick one of those up yet.

P.S. connector C110 is under the van, next to the oil filter (at least on my 5.4 engine)

Jack

 

Nothing special, it appears to just be a relay that is connected to the distribution block, and comes on with acc/ign with a 40 amp fuse. It goes to connector 110 where it becomes pin 9, as an orange wire.

 

Wow, this would of been much easier with the documentation that you have! Now that I'm finished with the project, I'm starting to get the drift of the terminology used in those drawings (wire color, connections, relays, etc)

Thanks again for your help and hopefully it'll help someone else in the future.

Any idea on how to silence the door chime even when the key isn't in the ignition?

Thanks again,
Jack

 

I just unplugged mine, but it's an 02. If you get your head under the dash while it's dinging, you will find the noisy box and plug pretty quickly. But, unplugging this will silence any other similar warnings, including lights left on, so be careful. Given the increasing number of beeps and chimes on newer vehicles, things may have changed and this may do you no good. I do realize its not a perfect solution, but it worked for me.

 

Jack,

Reviving an old post, if you are still on here. I'm curious, you say you bought a 7 way pigtail from the dealer. Did that harness have plugs for both the C421 and C422 on it? I am trying to find the appropriate harness to plug into the two to bring my trailer brake wire to the bumper. Any chance you still have any of the information on that? I'd like to identify the Ford part number for that harness. Also, as you had to splice in at C110, I'm assuming that you had to cut off the plug that would have mated with C421...any chance that you saved it (with enough wire attached to be used)?

 

Hello,
Yes, there is a connector for C421 and 422 on the pigtail from Ford. I don't have any info on the part number, but I think it's a pretty universal fit if you tell them what model year it is. I don't have the old connector, and if I remember correctly, I cut it pretty short.
Good luck with your project! With the wiring diagrams above, it'd be pretty easy to wire one in yourself fairly easily, and much cheaper.

Jack

 

No worries. Thanks for responding. After I posted that, I realized that having the cut off plug isn't going to help, as it wouldn't eliminate any butt splices. It would just move a splice from one side of the plug to the other. I'll just splice it in just in front of the C421 using a waterproof butt splice. It will be fine like that. I hate cutting wires where a proper harness could be used. But, somehow I think that even if I found the right harness, I wouldn't be willing to spend the $$ for it unless it was cheap on ebay or something. Plus, I'm guessing that the harness that you go was for a 7 way plug and I need a 6 way, so I'd probably end up cutting it anyway...

Thanks again.