Window Motor Replacement

Window Motor Replacement

Having got all the trim off the door you'll notice there are three access holes into the door internals. If this is the first time the door has been stripped (it was in mine), these holes will be covered by a polythene sheet glued to the door. I ripped this off, presumably it's to stop grease and general gunk getting into the innards of the door trim, so you might want to preserve yours. Through the holes you can see that the guide for the window motion is a greased vertical bar mounted centrally in the door, to which the bottom of the window is fixed by a running nylon clamp. This clamp has a horizontal runner rail attached, within which runs a small wheel connected to the lift assembly. The wheel itself sits on the end of an aluminium(?) arc with teeth on the outside edge. This arc is what actually moves the window up and down and is guided by runners and a pivot. The teeth engage in the cog on the motor, which is bolted to the assembly containing the arc. To replace the motor you firstly have to unbolt this lift assembly from the door, since you can't get to the motor bolt heads without doing so. Firstly g-clamp the window in the fully up position with a clamp just under the nylon collar. I used a small piece of foam around the vertical bar to prevent any g-clamp damage to an ideally low-friction surface. If you don't clamp the window, it will drop down heavily once you unbolt the assembly as described below, you can guess how I know this... Now pull the multiplug off the motor and unbolt the four bolt heads holding the lifting assembly to the door, these are obvious and between the access holes. Mine were really torqued up, so you may need a torque wrench to do this. As you undo the last bolt, hold the assembly through the hole furthest from the hinge, it's quite heavy with the motor attached. Once undone, manoeuvre the assembly to an access hole so you can see the motor bolt heads. All of this is done through the access holes, since the whole assembly is very awkward to remove completely (if possible?), but after some hand swapping and general limb gymnastics you should be able to hold the assembly with one hand and undo the motor bolts with the other, whilst simultaneously stopping the motor from dropping into the door! You can slide the wheel at the end of the arc off the window runner rail to allow the assembly to rest in the bottom of the door to make it easier. Once you've got the motor off, you can inspect it. I'd got an assurance from Kelvin at "AFN Reading" (a really nice guy), that if I didn't need to use the #213 ($340) replacement motor, I could return it, but unfortunately I did as the cog was badly rusted and the motor very weak upon testing. You can test the motor by refitting the multiplug and using the window switch. Conventional wisdom might suggest that you have the battery disconnected while you're doing all this...I didn't and nothing bad happened, and not doing so allowed me to test the motor and easily perform the adjustments required at the re-assembly stage. Fitting the new motor is simply a matter of bolting it back on to the lift assembly (through the hole nearest the door hinge). You may need to wiggle the thing a bit to get the cog to engage in the teeth of the arc. Having done this you now have to bolt the lift assembly back on to the door and this is the tricky bit. As you removed the motor, you will have probably moved the arc around it's pivot on the assembly and now having bolted the motor back on (and consequently locked the arc) and slid the wheel back into the runner rail, you are finding you can't get the bolt holes to line up in the door! This is where it pays to have the battery connected. Refit the multiplug on the motor and whilst holding the lift assembly within the door in one hand, adjust the arc's position on the motor by stabbing the window switch to create tiny adjustments. Don't overdo it as there is nothing to stop the motor strolling off the end of the arc, in which case you'll have to unbolt the motor again and move the arc back. Bare in mind the motor should be roughly at the far end of the arc, since the window is already fully up. This procedure should allow you to line up the lift assembly to the holes in the door and having done this you just rebolt and you're done. Don't forget to take the g-clamp off the vertical guide bar and grease all visible parts while you're there.

Author Unknown

The window regulator will come off the window channel with the window in the full up position (as well as full down). With the window in the full up position, I attached a small "C" clamp around the guide post, (padding the clamp surfaces as necessary to prevent damaging the post), removed the three aft-most 10mm bolts holding the regulator in. While supporting the motor with one hand, I removed the fourth 10mm bolt. This prevented the regulator from dropping down into the bottom of the door. I removed the motor electrical connector by prying gently in the little cut-out area between the motor terminal block (there is no locking tab to secure the connector to the motor even though it looks like there is). I then slid the motor/regulator assembly toward the back of the door, and the regulator arm slid right off the window channel.

With both hands inserted into the door access panel holes I maneuvered the motor/regulator toward the back of the door, angling the arm up toward the electric door lock assembly. I just wiggled it around a little until the arm cleared all the wiring and then the rest of the regulator came out without a fight.

Now I'm looking for motor brushes. New motors are too expensive!

Mike Gainey
86.5 Dunkleblau Otto


Go to an auto electric shop (rebuilds generators and starters). These shops actually work on a wide range of DC motors and generators, and will have a huge variety of brushes.

If they don't have an exact match, have them find one that is the same composition, and with the proper wire, but slightly larger physical size. Lay down a piece of 400 wet-or-dry abrasive paper, lay the brush on it, and machine to exact size.

Wally Plumley
928 Specialists

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