Door Locks - 98 Exp

[bc11]

Hello guys. It is time to move to other issues one of which is the door locks.

98 Exp XLT 4x4, 5.4L. All doors will lock and unlock with the key fob. The drivers door switch will lock all the doors but it will not unlock any doors. After driving and I need to unlock the other doors to let someone in, I have to shut it off and pull the key out to use the key fob.

So far I have replaced the driver door switch and looked for obvious wiring problems. I got a new relay but don't know where it is on the 98. I have read up and there are 3 possible locations for the door relays. 1 is in the dash under the oval panel on top of the dash below the windshield. 2 is in the driver's side passenger door. 3 is behind the driver's side rear compartment panel above the rear wheel well area.

If the new relay doesn't fix it then I will have to trace some wiring but either way I have to get to the relays to do. So if anyone can tell me where the relay is and have any other insight on the problem I would appreciate it. Thanks.

 

[bc11]

Hello all. I took the long oval cover off top of the dash, removed the metal bracket and got to the box with 4 spaces that contains 3 relays. Checking all the switches the relays fired like they are supposed to. Even swapped them around a couple different times trying them in different slots and they all worked. Checked the pink wire with green stripe that goes from the door unlock side against a ground and could make the middle relay fire and trigger all the door unlocks.

I checked all the leads on the driver's door switch that I've already replaced. Three black and a blue wire are all hot. Touching the pink wire to ground or jumping it to a hot wire fires the passenger side relay for the lock side. Checking from a hot wire to the unlock button while pushing the unlock button shows there is continuity with the button working so the switch is OK. Pushing the button does not fire the relay.

Finally checked the pink/green wire from the switch to where it goes into the middle relay on the dash and there is no continuity. Tested the pink wire for the lock side and it showed continuity so my continuity tester was working.

Question now is does anyone know where that pink wire with green stripe runs in there behind the dash? Like does it go to a fuse box or is there another connector inside the kick panel or under the dash? I haven't pulled the kick panel yet but will need to one way or another to look at the wire bundle where it comes out of the door.

Thanks.

 

[stamp11127]

What are you using to test continuity?
Once I get my home computer back up I'll look at the wiring diagram.

 

[bc11]

Thanks. Just used a regular test light with a longer wire attached.

 

[Bedrck47]

Prints for 98 power door locks

 

[bc11]

Thanks. It looks like the pink/lg unlock wire (following circuit B) goes from the all unlock relay and tees off at S255 and then on the way to the driver door it tees off again to the remote anti-theft personalty/RAP module.

S235 splits off to the driver and passenger doors. S255 splits off from the driver door circuit to go to the RAP module. I assume the bad wire is likely in the the bundle as it goes through the door hinge area so I need to see where it terminates after leaving the door. Are S235 and S255 connectors and if so about where might they be under the dash, if you know?

I have noticed that on top of the bracket under the oval cover is a square box or maybe it has relays in it but it has a bunch of wires that come into it but maybe that is where the connections are made. I don't know how ford does their wiring where it tees off. I assume they don't put splices into the bundle but in fixing the wire on my COP module I notice that ford has one hot wire that leaves the firewall connector and somehow splits off in the bundle to feed all four COPs. I also notice that the driver door connector has a place where 2 hots go to the same terminal and then another hot wire (all black wires) comes back into the door connector at a different terminal just like the wiring diagram of the connector shows. So do they put splices inside the bundles? Just seems like a weak spot if they do.

Thanks again.

 

[Bedrck47]

You may want to check the splices for any signs of corrosion especially if they are in an area where water could get on them Ford is noted for bad splice connections

And yes you will find splice connections inside of wire bundles

 

[bc11]

OK. I will pull the kick panel and find the bundle and check for continuity both ways and run a new wire from there or else run a new wire the whole length. Have to pull the door panel also. I don't know where the remote anti-theft module is but since all doors unlock and lock using the remote then there must be continuity between it and the unlock relay.

For the record I have ruled out anything on the fuse and power distribution side since I have power at all the power wires at the door lock connector. Since the door locks and unlocks from the passenger side button and the remote unit I have ruled out that it is a motor or solenoid issue in the door itself. I also checked the PCM wiring diagram and there is nothing to indicate the door unlock wire goes through it.

Guess I need to pickup some 18 guage wire or whatever it is.

 

[stamp11127]

Why not find the problem and fix it instead of running a new wire? The connectors are labeled with a C in the diagram, splices are labeled with a preceding S.

The COPs are all "hot" with the pcm switching on/off the ground for each cylinder. No need to incorporate the pcm for this.

In your first post you state the driver door switch will not unlock the doors, is it safe to assume that the relay in question is the "all unlock relay"? If so you should have power on 86 and 87a for that relay.

What circuits have you tested for power? Please specify by number, connector and print#. The first print is the one with the fuse, second has the two front door switches and the third is the one with the solenoids.

 

[bc11]

Ok. I found the RAP module on the firewall by the kick panel. It is a white rectanglular box and one of the wires is a pink/light green. I can see about 6 inches of wiring bundle there and that is it and a small wrapped bundle goes to the RAP module so the splice S235 must be in that area. If I go cutting into the bundle wrap I may end up cutting a bunch of wires and then I have a mell of a hess. I already had some close calls cutting into the pcm wire bundle when I replaced that COP connector. That wrap is hard cutting with a razor knife and one slip will cut a bunch of little wires that would be hard to fix.

The pink/light green wire does run into the unlock relay. Touching the terminal of it going to ground fired the unlock relay so it has power on the other side as it completes the circuit. Touching the terminal of the pink wire coming from the door lock switch to the all lock relay going to ground fires the lock relay so the relays have power and they all fired with the remote button and the passenger door lock button and did so even when I swapped around the relays.

The driver door connector C508 had 2 black wires going to #4 that showed power. The black wire to #1 showed power. The lt. Blue wire to #5 that goes to the illumination panel showed power. The pink/Y wire that goes to the lock terminal #6 had continuity to the all lock relay and also touching the test light to it with the other end clipped on metal fired the lock relay every time I touched it. The pink/lt green wire at #3 of the switch did not show continuity to the all unlock relay and also did not fire the unlock relay if I touched it with the test light going to ground.

So I am down to a bad unlock wire from the door lock switch to the dash area where the splice S235 goes to the RAP module. Sorry Stamp but unless I find an obvious break or bad spot when I pull door panel then I am just going to run a new wire as soon as I buy some. Still driving it for work so I haven't pulled the door panel yet. From what I've read on these boards the bad spot may be in the rubber boot between the door and the body and I don't really want to cut it open to look.

Thanks for all your help.