how to replace rear window regulator in '94 Lincoln town car

If the window doesn’t go up or down, but the motor makes noise when switched on, the problem is probably the motor or regulator rather than an electrical connection. First, check the motor, then if necessary replace the regulator.

A rebuilt motor for a town car is less than $50, and you might be able to save the old motor with $10 worth of nylon parts (see http://www.lincolnsonline.com/tech/00198.html). Items you will need to address the motor include: a tool to pry off the interior door panel (less than $10 at the auto parts store); a box of 100 drill bits from the hardware store ($12), and a screw driver that will take the bits (screw driver bits normally have a dimple, but these bits don’t so you need to get a screw driver that will take a drill bit); and a nylon parts kit (Dorman sells these) if you decide to go that route rather than replace the motor.

1. Remove interior door panel. First, carefully pry off the plastic door pull caps, then remove the screw on each side of the door pull. Next, remove the door latch cover screw and cover. Then remove the screw on each side of the door panel near the top. Now you can pry off the door panel with the special pry tool. You will have to disconnect the wiring. Twist off the courtesy light socket from its housing; disconnect the window switch from the control panel (two screws); and disconnect the cigarette lighter.

2. Peel back the flexible weather shield from the bottom to reveal access hole in the lower-middle of the door. The cover might be anchored by plastic fasteners, which come out easily with the pry tool. The edges of the plastic cover may be lightly glued. Tape the cover up out of the way.

3. Disconnect the motor from the door. The motor snugs up to the plastic regulator gear casing, both of which are anchored to a mounting panel by three screws. This panel is anchored on the other side of the inner part of the door with three rivets. All you can see at this point are the three rivets (unless you put a mirror in the door cavity). One approach is to knock out the rivets, and take out the panel (see http://www.lincolnsonline.com/tech/00056.html). Another approach is to drill holes through the door panel to access the screws (see http://www.lincolnsonline.com/tech/00198.html).

The three screws holding the motor and cable box are funny. They appear to take a #4 “Robertson” bit (square), but I eventually stripped the heads using that bit. At that point, however, I found that a star bit fit perfectly. The screws are available only from a Ford dealer at $6 a piece.

Once the three screws are removed from the motor/cable box, you can separate the them with a flat screw driver and a spray of wd-40. If the motor makes sounds and the gear box looks okay, you might be able to just refurbish the motor by replacing the nylon parts that are in it and call it a day (see above).

4. Replace regulator. If replacing or refurbishing the motor doesn’t do the trick, or the regulator is obviously defective (for example, the cables are all pulled apart), then you will need to replace the regulator. You will need: a regulator (I got one for $28 online); a cheap riveter ($10) and some rivets; an extended length ¼ inch (I think) ratchet to reach recessed nuts on the regulator; some ½ inch long # 20 hex bolts and lock nuts; some plastic fasteners for the interior door panel; a #904 bulb (from auto parts store); spray Teflon lubricant (Ace carries it); and a new ¼ inch drill bit that can go through metal.

5. Working with pop rivets. Although you can replace many rivets with bolts in this project, it’s not possible to re-attach the door handle bracket without rivets. Pop rivets are easy to master. Most of the holes are ¼ inch in this project, which is an industrial size. Riveters sold for normal people top out at 3/16”, but that’s okay. Large 3/16 rivets will do the trick. A pop rivet has a plug at one end and a stem at the other. Put the stem in the tool, and push the plug into the hole. Hold the tool tight against the surface, and squeeze. The plug will be in, but loose. Squeeze again, and the plug will be tight. Squeeze again and the stem will pop off.

To remove a rivet, use a fresh ¼ inch drill bit suitable for metal. Point the business end against the center of the rivet head, and drill until the head comes off on your drill bit. Then take a punch and a hammer, and hit the center of the rivet until it pops out. You should run the drill bit through the hole to get out all the pieces. It’s a quick, if noisy process.

6. Remove the door handle bracket. This is held by four rivets. The bottom holes are ¼, and the top ones are smaller (maybe 1/8”). You can treat the top holes as ¼” for these purposes if you run the drill bit through both the hole in the handle and the corresponding hole in the door to increase the size. Alternatively, you can simply use a smaller drill bit for those top holes, and a smaller replacement rivet.

7. Completely remove the flexible weather shield by removing any plastic fasteners, and peeling it back carefully. Also, remove the door latch, which is held into place by two screws. Pry up the bottom inside weather strip with your pry tool.

8. Remove the window (the hardest part). First, loosen but do not remove the bolt near the bottom of the door that’s off to the side. That’s the track adjuster and it needs to be loose to allow the window to fall out of the track. Second, there’s a metal bracket on the bottom of the window fastened to the regulator by two rivets. Position the window so that all of this is in view (you may need to cut the old regulator cable). Put a towel in the door in case the glass falls. Third, punch out the two rivets (remember, mechanics do this everyday without breaking the glass, so keep your nerve). Fourth, wiggle the window out of its track (gravity helps). Then push/pull the glass up, and try to tilt or pivot it to the side (it won’t come out straight up). It’ll come out cock-eyed, and towards the interior. Fifth, take the window and show your wife. She'll be so proud of you.

9. Replace the regulator. It’s all downhill now. Remove the two recessed top nuts holding the old regulator, and punch out the lower rivets. Pull the regulator out, and compare it to the new one to see if they sent the right regulator (the holes for the window fastenings should line up). With the door cavity as empty as it’s going to be, generously spray your Teflon lubricant deep into the tracks. Then clean out the bottom of the door (you don’t want loose metal rattling around in there). Then, put in the new regulator, and tighten the top bolts finger tight. Now you can either bolt the bottom to the door, or rivet it. This is a good place to try your first rivet.

10. Insert the window, attach, and adjust. With gravity as your friend, lower the window into the door and snug it as best you can into its track. Use ½ inch long, #20 hex bolts and lock nuts to attach the window to the regulator. Raise the window to the top, and tighten the top nuts (don’t over do it or the bolt will pop out, in which case you can insert a short bolt in its place). Then lower the window all the way and tighten the track bolt. Lubricate the rest of the window track. Slide the window up and down. Ideally it should move pretty smoothly, but if it binds a bit near the top and bottom that’s okay as long as you were careful to tighten the top nuts with the window up, and the track bolt with the window down.

11. Put the motor back in place. Spray the gear box and motor spindle with wd-40 if you haven't already. Match up the motor with the gear box, and insert the spindle into the box. Then replace the motor, retracing whatever steps you took in removing it. Connect the motor to the power, and test. Note that if you negligently didn’t bother disconnecting the battery, there will not be enough juice to operate the motor at this point, even if the interior lights are still on. Jump start your car, and test.

12. Re-install the weather shield, and rivet the handle bracket back into place. You can do bolts on the bottom two holes, but you can only do rivets at the top. Re-install the weather strip (gentle prodding with a rubber mallet helps).

13. Replace missing plastic fasteners on inside of interior door panel. I bought some at the hardware store, and then trimmed the heads to size with a wire cutters so they’d fit into the handy receptacles in the door panel.

14. Re-attach electric cables to the door panel. Replace the courtesy light bulb while you’re there (simply pull out old bulb and insert the new, which for some reason is a bit larger). Screw the switch back into place, and reconnect the lighter.

15. Mount the interior panel onto door. Hook over the door lock spindle, line up the plastic fasteners, and bump the panel into place with a rubber mallet. Replace screws, door pull caps, and door latch cover.

16. Suggested maintenance. Lubrication with Teflon spray makes a huge difference, so spray exposed window tracks regularly, especially near the top. If you get ambitious, remove the interior door panel, peel back the weather shield, and spray the window track in the door. While you’re there, replace the bulb for the courtesy light. For the very ambitious, you can service the motor by replacing the nylon bits, and lube the regulator gear box while you’re there.

17. A word about motor removal methods. I used the hole-in-the-door method rather than the remove-the-rivets-and-pull-out-the mounting-panel method. It's ugly, and takes a while, but once you're done with the holes, it does make removal easy. Next time though, i think i'll remove the rivets and take out the mounting panel.