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There are Mercedes alternatives that we sell for circa $100. Both types.
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Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
I have a question about my window motor. I had it apart, all cleaned up. I have 11.9 v at the plug, when plugged in all I hear ( with stethoscope ) is a static like noise when switch is operated. When it was separated I did a continuity test, it showed there was some resistance at the brush after the little black box, is this correct? Also does the motor need to be bolted on to achieve a proper ground for testing, I only connected it with clips and a wire. Thanks for any help.
Justin
You should be able to test it with a 9v battery and it should turn the motor. If not you may need to rebuild it and clean out all the old hard grease from the gear box with spirits and add some new light grease. Don't pack it. Just add enough to lube the gears. It does not need to be bolted to car to test the motor.
Thanks for the reply. I have cleaned it thoroughly and inspected all contacts, it all seems to be pretty nice. Nothing seems to be bound. Crazy thing it worked really nice then stopped ,I put in a new switch, old switch seamed bad,(not it ), took off door card etc. and it worked! up and down several times, got rags to clean up , stopped working. Motor is on bench now again, all apart. Aside from the slight resistance I cant find anything.
I have about 5 or 6 motors I rotate parts in between. Half of those motors work sporadically. Now, keep in mind, I need new door guide trim, so I get water in the motors a lot. I clean the passenger side motor out at least three or four times a summer. I have to start re-sealing the motor where the factory seal is (and by the connector).
I've cleaned EVERYTHING - I've even used dental picks to clean the crud out in the fine lines on the big motor.
I've found one reoccurring part that seems to be a bug. The two springy contacts that the top of the motor spins against can stick. If one of them sticks even a slight bit, it tilts the motor ever-so-slightly to the left or right and it jams. The key is to keep those springy things very lubricated.
If the motor works consistently on the bench but intermittently in the door, you should check for broken wires in the door.
The wire harness in the door flexes as the door is opened and closed which over the years fatigues the wires and causes them to break.
Sometimes the conductor in the wire breaks but the insulating sheath is intact so the broken wire is not visible.
You can gently stretch each wire individually, and any with intact conductors will not stretch at all, but any with completely broken conductors will; you can see the insulation get thinner over the internal break.
I believe that the wires for the window motor are heavier gauge than the rest of the wires in the harness.
I just went through the motor R&R and thought I would add some additional pictures and details.
Here is an exploded view of the brush assembly and springs.
If you do an ebay search for the Brose part number you will find several Mercedes and Saab uses of the same motor. Replacement motors are about $20 -$30.
06-15-2011, 08:08 PM
George Layton March 2014
