Urambo Tauro

1995 Mustang GT, 172,000 miles

Yes, it's a 5.0, and I've posted a thread in that section, but I'd like to hear you guys' input too, as I expect that the SN95 wiring should be the same.

I'm having a problem where the switch on the driver door LOCKS both doors but will not UNLOCK either door. Everything else in the system works properly, unlocking and locking both doors. The passenger door switch works fine, and my remote key fob works too. Only the driver door switch's UNLOCK feature is inoperative.

I removed the switch and tested it; the switch operates fine, providing continuity to the unlock circuit when the "U" is pressed. I checked my wiring diagram, and the pink/green unlock wires from either door meet somewhere in the middle before going the RKE module. I figure there must be an open in the circuit somewhere between the switch and this junction.

The driver's side pink/green unlock wire runs from the door, through the snake, into the car, and immediately goes up into the dash somewhere, behind a bunch of stuff. Where is it routed? Can I pick up the trail again somewhere downstream without having to pull the whole dashboard apart?

Urambo Tauro

Well, I ran a jumper from the pink/green-striped wire at the passenger side switch to the master switch on the driver's side. This causes the driver switch to operate normally, confirming a problem in the wiring somewhere.

After poking around some more, I found a rectangular 16-pin connector (which actually has only 14 pins in use), with a pink/green wire in the corner terminal. This connector is located up underneath the dash, next to the steering column.

This pin has continuity to the passenger side, but not the driver's side. Now if I really wanted to, I guess I could splice in a wire from this point to the driver door. But I'd really rather find the open in the circuit and see if any other circuits are in danger of doing the same thing due to chafing, corrosion, or whatever it may be.

I'm afraid that I might have to pull the dashboard after all. Any suggestions before I do?

Urambo Tauro

I found it!

I got myself one of those inspection scopes, and started snooping around with it. Sure enough, I found the broken wire in the snake between the door and the body. It was not chafing on anything; it just didn't like two decades of flexing back and forth.

There's very little room to work with, so here's what I did:
I couldn't quite figure out how to get to the connectors to disconnect the door wiring completely, so I worked with the interior door panel removed. The snake has a very large grommet on the door side, so I dislodged it and pulled it along the wire loom into the door skin. There was still very little room to work with, and not much slack in the wires either. So I installed a few inches of fresh wire between the two broken ends and reassembled everything.

As you can see in the attached picture, I found a second broken wire. I wasn't expecting this because everything else seems to be working, including my windows and mirrors. The broken wire is white with a light blue stripe, and my book says that it is for the "door handle switch", and runs back to the RKE module.

What is that switch supposed to do? What happens if I don't repair it?

Camster

Congrats on figuring out the window issue.
I had the same sort of "broken wires from flexing" issue with the tailgate of my Taurus wagon.