Hi guys,
I posted this over in the towing section but havent gotten much traffic. Can you help me out?

Okay, so I am finally digging into installing a 7 pin connector and brake controller on my '88 E250. It had a 4 pin that the previous owner told me he had spliced in. I unwrapped the electrical tape and found this

I then started digging under the dash and found this

Now does this mean that at some point this vehicle already had a 7 pin/brake controller and that this is the wiring for it? If so, I should be able to just add the 7 pin and hook up the controller to the existing wiring....correct?
Thanks

 

That looks like 7-pin wiring at the rear. If they're hot I would just connect to those. Not sure what that plug is under your dash. It looks like a airbag disconnect.

 

Thanks. I will get my meter out and start testing. Would they have an airbag plug on the harness in 1988?

I am assuming that the harness would have to be some kind of aftermarket one since I don't think Ford installed them from the factory in '88. The yellow plug looks like ones that I saw plugged in to what looked like the rear taillight wiring near the hitch. Worst case I can start tracing the wires back.

 

My 88 had some wiring that looked stock, I don't remember how the wires terminated in the cab, but it wasn't a yellow plug like that. They may have just been cut ends? Not sure what the previous owners had done...

I would just trace the wires, thats the best bet and isn't really too hard.

 

the conector under dash is brake controller prewire...check with volt meter ,,the green with black should be hot constant..yellow wire,,and blue just run to back of truck,,sometime also red,,depending on year,,at back of truck should be a plug,,three or four wires,,green (power for charging batt in camp trailer..blue (brakes),,yellow most often used for backup lites,,red is used for some older brake controlers,,

 

Look behind the bumper where your tail light box harness connects to the main harness on the frame, it will be on the driver side, if there is extra plugs or that is where your trailer wires already go to then your truck dose have the factory towing harness in it.

 

in ref to the yellow plug -- what are the exact colors of the wires leading into it ???

like red or red w/yellow stripe or blue w/red stripe, etc.??? I've got a wiring schematic - maybe I could find it......

 

FYI yellow plug under dash is NOT an air bag connector just to clear any misconception.

While manufacturers do use yellow and orange connectors to identify air bag circuitry, they do not install connectors that do not have a safety interlock.

Thats all I got

 

Yes there are extra plugs that the trailer lighting is plugged into. The 7 wires from the trailer wiring seem to be split into groups of about 2 and each group plugs into a separate connector that goes into the main bunch of wires that run toward the front of the van. They are all connected except 1 that I could easily plug together. Wire colors on each side of the plug are identical. Here are the color wires I have:
Rear of van.....yellow w/black stripe, brown, black, green, blue w/black stripe, red w/black stripe, black w/yellow stripe.

Plug under dash.......red, Lt Blue w/black stripe, Drk Blue w/black stripe.

I looked briefly under the dash and did not see any other loose plugs or terminated wires.

 

Your van looks to have been equipted with the trailer tow package from the factory. In your first pic, the wires hooked to the 4 prong are
green-right turn
brown-trailer running/marker lights
yellow-left turn
black to white on the 4 prong-ground
The 3 that are taped together, if they are the same as an F-series,and if I remember right are
blue-trailer brake
red-trailer battery charge
black with yellow tracer-trailer back up lamps

The plug in the second pic is probably for the brake controler.

 

You should be able to find a factory camper plug in in a junk yard that will plug right into the back of the van, if your lucky the junkyard one will have a break controler that you could rob too.

Some how I missed the part that it was a van, I was taking about a truck, but I'm not sure if there is or in't a diffrence.

 

Figures, the one time I didnt search for a thread, this one was only started a few days ago, oh well, this helped me too. from whats been said i believe my truck has factory towing package and wiring to be able to run the brake controller, Im also going to follow this thread, see if it goes any farther...