My dad drove a lot of different cars home from his garage. One morning in 1963 I remember looking down the long dirt road in front of our house at the approaching school bus, and I glanced over my shoulder at Dad while he slid behind the wheel of a long black car to leave for work – I still don’t know if that grand old boat was a Cadillac or a Chrysler, but I do remember the goose bumps I felt when I saw all four of the windows slid down into the doors under their own power.  When I was six years old, it seemed more like magic or science fiction than reality.

According to some sources I found, Daimler first introduced electric windows in 1948, but the SAE timeline credits Lincoln with the first power windows in 1946.

My wife is a drive-through bank teller, and she says one in four of her customers have a driver side front power window that is inoperative; they have to open the car door to do business. Any shop owner knows there’s a big profit in power windows.

The old scissor type regulator with its curved rack and spiral spring were by no means trouble free, but they didn’t drop like flies the way so many of the cable and pulley units do nowadays, either – usually all it took on those units was a motor or a switch. 

Initializing the rear window motor on a Ford Sportrac

Motors and regulators obviously aren’t the only problems with power windows, although they’re generally the most expensive repairs.  I say generally because some Japanese cars can have pretty expensive switches. Example:  The driver’s side switch on a 2004 Camry lists for $356.67 (the regulator is only $101 and comes separately from the motor, which is $280).  The same switch for a 2001 Jeep Cherokee lists for $139.00. 

A 2001 Mazda 626 driver side switch runs just over $300, but that same switch for a 2004 Mazda Six is only $104.  Go figure.  On a 2004 GMC Envoy without heated seats, the driver side switch is $229.83 (the driver’s window motor is $115).  Regulators are all over the place, from a little over $100 to well over $300 on most of the cars I checked. Volkswagen switches and regulators tend to be less expensive, but the window motors on a 2001 VW GTI are $319. 

 Failed Dodge Caravan Regulator - note the tangled cable

Speaking of German cars, the window regulators, motors, and switches on Mercedes automobiles are very reasonable, usually costing only a fraction of what those parts sell for on Japanese platforms.  The window regulators on Jaguar automobiles run from $600-$700 and the motors can be about $50 on either side of $500. 

Can anybody say “ridiculous?”  This could go on for awhile, but you get the picture.  Fixing the power windows on some cars can be more expensive than a salvage yard engine for the same car.

A

 Moisture barriers like the on on this mid-90’s Mitsubishi Montero are the first thing you see when you pull a door panel on a previously untouched vehicle. They were made of special paper on older
cars, but were upgraded to plastic about twenty years ago. And while it’s very tough trying to peel one out of the way without destroying it, the barrier is really important, so do what you have to in order to seal it up again like this when the job is done, even if you have to repair the torn barrier with packing tape.

For my purposes as a technician at the Ford/Jeep dealer, I’d operate the switch on a dead glass (scissor-type regulator) and watch the dome light or the instrument cluster voltmeter:

If it reflected a heavy battery draw while I was trying to get the window to move but the window didn’t respond in the desired direction (down if it was all the way up or vice versa), that generally meant the switch was working and the circuit was complete, so a motor was in order.  In those cases, simply removing and reinstalling the motor would un-jam things for a temporary fix, but that’s all it was.

From what I’ve seen, the inner skin on those doors tends to become more flexible over time and cause this jamming effect. If operating the switch didn’t dim the dome light, then there’s an open circuit somewhere. 

Don't try this without a schematic of your car's power windows!

Power window switches are generally wired in series the way you see here. For that reason, a bad driver side switch in the master power window switch assembly can cause the passenger side window motor not to work from either switch.

Both wires feeding the motor should show ground whenever both switches are at rest. If either wire doesn’t show ground, check the wires coming from the master switch. If they both show ground on the incoming side of the passenger switch, then the passenger side switch is faulty.

If, on the other hand, there is no ground being fed to the passenger side switch from the master switch and the wires are good, the master switch is faulty. Remember now, if either wire is shorted to ground, the window will work, but only in one direction. I’ve seen that a time or two.

Nowadays, almost invariably, what I’ve seen is a motor that still runs, but the regulator it’s bolted to has become a tangled mass of junk.  The most odious circumstances revolve around a window that’s down and won’t go up in a rainstorm or in cold weather; like a bad timing belt, those failures don’t generally pick a good time to happen.

 Dorman Power Window Regulator for the Dodge Caravan.

Ford power window motors that drive those old spring-and-scissor regulators have breakaway gears that are prone to give out, and when I operate the switch for a particular window hear the motor running but not moving the window and making that bumping noise I know the gear is shot to heck; and while they weren’t initially available, nowadays, aftermarket gears can be bought at the dealer parts counter as well as at most parts houses. Further, the gears aren’t that expensive (about $20). They’re and fairly easy to change, but the labor charge is the same as replacing the motor. 

To do that on an older Ford, just yank the door panel, look in the general area where the motor is located, and you’ll find three center punch marks that correspond with the screw heads that hold the motor in place.  You’ll need a 3/8” or larger drill bit to make a hole big enough to egress a 5/16 socket.  After you drill out the center punch marks, just look through the holes and there are the bolt heads.  Sometimes you’ll have to remove the door speaker to get the motor out.

The bumping and thumping that comes from those failed Ford gears results from the fact that the outer gear and the inner gear are no longer turning together; the little plastic pucks that marry the two-piece gear together tend to crumble, and they look as if they are designed to do exactly that, possibly in case of an overload situation, but I’ve never seen that in writing.  The helical outside ring gear on the business end of the window motor is driven by a worm gear to provide the necessary torque to raise that heavy glass (albeit with that powerful spiral spring adding lift), and the inner pinion gear meshes with a curved plate that is a part of one side of the scissor regulator.

We fix quite a few power window problems in my automotive department at the college; late model GM cars have lots of power window problems, and at the dealership it generally costs about $400 per door to replace the regulator, which comes with the motor, but it’s a bolt-in part instead of being held by rivets like the Crown Vickies and rear door regulators on late 90’s Ford Explorers.

 Chevy Trail Blazer Regulator - New.

For awhile, Explorers used the scissor type regulators in their front doors and the cable and pulley units in rear doors.  Late ‘90’s Dodge Caravans have cable and pulley units, but with two tracks instead of one, and they can be a bit confusing to figure out if you aren’t paying attention when you snatch the old one.  The Dodge Caliber has an entire panel that can be removed to access the power window hardware.

Crown Victoria window regulators are the same type but are available from aftermarket sources (like Dorman) for a fraction of what it costs to replace a GM regulator, and Dorman is making more and more replacement regulators available all the time.  One example of a fairly recent Dorman release would be the front window regulators on some Chevy Trail Blazers, and one October issue of Motor Age had a dandy Dorman chart on what’s available.                                                                     

Power Windows are ubiquitous, usually easy to fix, and as necessary in our vehicles as the A/C.  

R.W.M.