Power window and door lock switches are really strange. Maybe you can lower the rear windows from the driver's console but not raise them again. Maybe the driver can raise and lower the passenger window but the passenger's switch won't work. Or maybe you clean the passenger's door window switch and it works but the driver's control for the passenger window quits working and then both quit working a few days later and you clean and poke and finally get the passenger window up again. And maybe the passenger can't power the door locks. Maybe sometimes the driver's window won't go up unless you pry open the switch cover and jiggle a wire or two.
Maybe nothing. All of this is my current situation on my '91 XLT.
I have done a thorough search of threads and much has been written about correcting these problems. RiverRat wrote how to test to see if there is a motor problem vs. a switch problem -- open a door so an interior light comes on, depress a switch and see if the light dims -- If so, motor problem; if not, switch problem. Brock 94 wrote of a ground wire issue and Moderator Robb wrote about direct wiring the 12 v. feed from the battery. Someone else pointed out what is probably the most common problem, dirt and gunk in the switches. Assuming a wiring/conductivity problem and not a motor problem, here is what I have found, and at the end of this post, an apparently new idea is posed to run up the flag pole to be saluted or cut down. Please let me hear from you.
I have disassembled the driver's master switches and the passenger's switches on my '91 XLT and here is what I find: it is easy to pry open the cover holding the switches. The switch boxes in turn easily unplug from the wiring harness. A small screwdriver can then be used to pry open the switch box cover by depressing small flat plastic pins. You will then see the guts of the switch and note that the plastic U and D (or L or U) toggle depresses tiny copper (don't know the technical term) spring switches, sort of like old fashioned telegraph keys, and electrical contact is thus made when the copper telegraph key is closed by being depressed. Because copper can tarnish or just get dirty, gently cleaning and filing the contacts with a very small flat file may help. But filed copper will in turn tarnish more quickly. The telegraph keys are also very delicate and could be bent, misaligned or lose their "spring". The switches in turn plug into the wiring harness via copper pins. These pins too can be tarnished or dirty and should be cleaned.
But here's where I think the weak link is --the copper pins (the switches) plug into female receptacles apparently made of aluminum. These are little aluminum bands shaped into a circle, a hole, sort of like the spark plug wire connector on a lawnmower. So, electrical conductivity depends on a tight fit and clean metal. Wires are soldered to these tiny female aluminum receptacles, thus the bundle of wires and the female receptacles (imbedded in a plastic box) make up the wiring harness assembly. I took a small rat tail file and alcohol and tried to clean out the female receptacles. Hard to do, and again, filed or scratched metal in turn tarnishes more quickly.
When I reassembled both sets of switches, the passenger's window switch worked great for about a day then quit again. No effect on the driver's side switches other than the driver's window now works all the time, but the driver's master switch won't so anything for the passenger windwow (it formerly lowered but would not raise the passenger's window, go figure.) I disassembled the passenger's window switch again and was able to get the window up by depressing the copper telegraph key with my fingers.
The next day, even that didn't work. The window was stuck down again. So, for a mere $18 and change, I bought a new passenger side window switch from the Ford dealer. The new switch had no effect. So, my initial conclusion was that the problem was with the aluminum female receptacles, not the switch itself. Only after a thorough cleaning of the fmale receptacles once again, much anguish and basically repeated toggeling of the NEW switch did the window go up again. These female receptacles are the weak link.
Research of prior threads indicates that one or more wires is critical to grounding and transmission of power. One post said the ground for all switches runs through the driver's door lock switch so that swithc is a critical link. So, any one switch or wire (female receptacle) could be affecting functionality of others. Very complicated.
I removed the door panel and find that the wiring harness disappears toward the motor buried deep in the door. So, here is my idea for comment: if, and a big if, I can buy a new wiring harness for both front doors with the aluminum female receptacles attached, I am thinking about cutting off the old wires and splicing the new wires to them, so I will now have new switches with the male copper pins and new female receptacles (still old wire leading to the motor but probably sound wire) and thus solve the problem this way, on the relative cheap. New plugs, new receptacles, no cleaning and filing necessary for a long time.
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Thanks 410 for the reply. I guess you can tell from my post I am not exactly Mr. Electricalbrain. I still wonder why, when you unplug something, the electricty doesn't drain out of the wall. By "switch" I meant the plug-in assembly which includes the exterior plastic rocker switch marked U and D or L and U with the interior copper guts and the pin plugs which plug the whole "switch" into the female receptacles in the wiring harness. By relays, do you mean the copper mechanisms inside the swtich box that the plastic rocker buttons depress? I may try some type of conductivity spray from Radio Shack and again carfully file and clean every single connection. The wires all look solidly connected but I guess a wire can fail internally.
Thanks again.
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After much research of threads and input from 410 Fortune, I have resolved the problem of malfunctioning and "no functioning" power window switches and power door lock switches. Thread search solutions ranged from cleaning switches and contacts to hot wiring power, replacing motors, fuses, relays and the like. On the simple theory of trying the easiest first and starting at the source before chasing the problem elsewhere in the car, I cleaned all switches and contacts and, magic, all functions have been restored. Here is what I did, so maybe you can try it too. This was on a '91 XLT 4 door. Concepts should be similar to identical on most Phase 1's.
1. I first replaced one totally non-functioning power window switch (the front passenger door) with a new one with no effect. Don't do this until AFTER cleaning fails.
2. I read in one post that the wiring of the door lock switch contains the ground for all door switches, window and lock. So, I decided to carefully but thoroughly clean all switches and contacts, not just the malfunctioning power window switches.
You will need a pair of small slotted and one Phillips head screw driver, some rubbing alcohol and Q-tips, some electrical contact cleaner (Radio Shack - try to get a spray can with a brush attachment for scrubbing), an old soft toothbrush and some towels or rags to protect the interior from tuner cleaner as you work. Also use a small cup or tray to hold small parts.
3. Starting with the front passenger door (the easiest), gently pry the switch button assembly out of the door using a slotted screwdriver. There is a slot for this on the rear edge of the plate surrounding the switch button. The other edge has two small hooks that grip the door's cut-out for the switch plate. When you pry up the rear edge (there is small spring clip which you depress with the screwdriver), you can slide the cover plate gently backwards and the switch button and the plate will come free. Just take your time. The attached wires will extend a few inches by gently pulling. NOTE, the rear windows' switches look identical but have a healthier spring clip holding the switch cover plate down. Just be very gentle.
3. Turn the cover plate and switch assembly over. The switch assembly is attached to the cover plate (which holds the switch assemblies in place) with two Phillips screws. Gently remove them. If they won't easily turn, don't force them as you may snap off the plastic instead, as I did. Loosen a tight screw with contact cleaner or WD 40 or whatever.
4. With the screws removed, the switch assembly will then slide out of the cover plate. Set the cover plate aside. There will be one switch assembly for the door lock and one for the power window. They are attached to the wire harness plugs (female receptacles) via brass (male) pins. These pins are substantial so you can pry the plugs up with a slotted screwdriver to get them started then unplug them with your hand.
5 The switch assembly is now free of the wiring harness and receptacles. Carefully inspect all wire connections where the wires connect to the aluminum female receptacles for the switches which are imbedded in a plastic assembly. Repair any suspect connections by re-soldering. Details of soldering not discussed here.
6. Now remove the plastic switch assembly cover (plastic box) containing the external plastic rocker or toggle switch (marked L or U or U or D). Note the four plastic pins holding the very thin plastic box on. Gently, gently pry the side of the box over the pins until the bottom drops out, revealing delicate copper "telegraph" switches attached to the copper pin plugs.
7. Cover the work area and the inside surface of the door with towels or rags.
8. Clean any gunk inside the cover box with alcohol and Q-tips and clean around the external plastic switches the same way. Do not use Q-tips on the copper telegraph switches as they will shred the cotton and foul the contacts.
9. Liberally spray contact cleaner all over the copper telegraph switches and the pin plugs and gently scrub inside the guts of the switch with the brush provided with the contact cleaner can or using an old very soft toothbrush. Spray again and leave to sit and stew.
10. Liberally spray contact cleaner inside the female receptacles attached to the wire harness and aggressively scrub inside the receptacles with a small brush. Spray again, scrub again, then spray again and let stew. I suspect these female receptacles are the real weak link in the electrical connection.
11. Wipe off and replace the box cover of the switch assembly, then again wipe off any remaining excess contact cleaner. Wipe excess contact cleaner off the wiring harness assembly and plug the switches back in.
12. Turn on the ignition ACC switch or the engine and test the switch, both at the door and from the driver's master switches.
13. If at least the door switch works fine, reassemble everything and move on. If not, repeat the cleaning at least once more. If that's doesn't work, you have other problems. Search the threads for ideas. As a next step, try replacing the switch. A new one from FORD for the passenger door costs about $18. The driver’s master switches cost about $85. Otherwise, there are lots of threads on this issue. In my case, the switch was fine. The contacts were compromised. Cleaning did the trick.
14. For the driver's master switches, the process is pretty much the same except the switch cover box for the power window switches (4) and for the window lock push button switch is all one piece, and the thickness of the bundle of wires makes it a little more difficult to manipulate the assembly while you remove the screws that hold the cover on. The pins holding the switch assembly cover on, this time 8 instead of 4, work the same way, but the big switch box cover won't come off until you also remove the push button window lock switch (button). It removes by being lifted straight up. It has a female square hole that fits over a white plastic (male) tab, about 1/8th inch square, which is attached to the wire harness. This plug is a tight fit and takes a bit of urging to get off. I used a small flat head screwdriver but you have to be very, very careful and patient and don’t twist the button. Try and lift it straight up, maybe using two screwdrivers at once. (It’s hard to grip with just your fingers.) Once the push button is off, the cleaning and re-assembly process is the same as with the passenger door. Replacing the window lock button, press firmly until you hear and feel it snap into place.
The rear doors contain only a power window switch and no door lock switches but, again, are a bit more difficult to get out of the door initially.
I had great success with cleaning, but I did so very carefully and very thoroughly. I still broke off one of the screw attachments and had to super glue it back with some plastic strips for bracing. Be gentle, work slowly, protect your car from fluid, and good luck.
