Power windows, O.E.M.. Front-rear, investigation, service.

This is nice, ( but it is not the O.E.M.).

The dream of the electric, power, windows, in my case, was already materialized by the manufacturer.

Twenty five years after, everything is working properly, except a crack noise from the front right window.

The total installation is computerized an has these extra functions:

1)It is torque sensitive, so if a child's hand, (f.ex.), is blocked within the frame, the motor stops immediately.
2)It has a thermal protection, so after many consecutive ups and downs, (and if the U rails are modified by the owner in order to minimize the play and the noise when the door is closing), the controller shuts down the motor for a  few seconds.
3)The windows are opening and closing sequentially, offering the maximum protection against controller and lines/connectors overheating.
4)Locking the doors, (electropneumatically), all the windows are closing, (if you keep the key turned for few moments).
5)The way of closing changes according to the vehicles speed, (at high speeds, one touch closing).
6)The system is functioning for one hour after the ignition shuts off.
7)Drivers window works only with ignition on, for safety reasons.

So back to the initial reason for this investigation, the crack noise.

The weak welding points, (red ellipse), are not strong enough to carry the load, since the frame is not sitting on the mechanism's frame, but there is a gap, (yellow rectangulars).
(Driver's window).

The solution:

1)Elimination of the gap between the two frames.
2)Adjustment of the home position of the glass into the frame, (few mm higher, supports, within the U holder, for the new home position of the glass).
(3)Hammerite painting, transforming the rust to magnetite).
(Passenger's window).

After these, the crack sound disappeared.

Some more elements from the investigation/service procedure.

The inner side of the drivers door, after some cleaning, still perfect, (25 years of use).

D.I.Y. inner membrane, gluing the point where water is coming in, rear doors, power windows line.

Here you can see a point from which water comes in through the cable for the motor, since it has a wrong angle.

The original membrane intact, for historical reasons.

The drivers side mechanism.

1992, Siemens/Brose.

Home position regulator, anti noise pad missing.

The missing, (graphite contained), pad is like this. Found one from a Mercedes similar mechanism.

Teflon reinforcement of the home position regulator, since the plastic pad had an abruption tendency.

Opening the gear box.

Perfect condition, needs grease.

Motor must be opened.

The strange findings. Debris from the brushes? Or dust from the, non filtered, ventilation hole? (On the bottom right inside the shell)

The rotor in perfect condition, though.

The collector after cleaning. Signs of some, light, wear. This, (drivers), is the only motor having some wear. The rest three are in a brand new condition.

Stator after thorough cleaning/greasing.

Grease cap for the ventilation hole.

The rear right mechanism.

Rear right window rotor. Water invasion from the ventilation hole? Strangely enough, it works perfectly.


The rear mechanism, as a total. The motor is supported on three silent blocks.

Motor-Gear box with two sock absorption  springs.

The gearboxe's lid. Signs of humidity or water.

It works perfectly but needs fresh grease.

Grease for the sock absorbers, too.

And for any other point needed, such the above.

Fighting the noise.

Extra noise eliminator, into the gasket of the glass. No noise at the door closing, even if the window is open, at the maximum noise position.

With the help of one of the  magic materials: filter hood for life time service.

Adjusting the gap of the rail spacers from 1.4 mm to 0.6 mm..


......that's all folks.

The windows are working now better than ever and the noise of the closing doors is, really, perfect even with the windows open, which is the most difficult part of all.
(StilĪ™ I do not like the sound of the expansion valves which compensate the cabine's pressure for an easier closing of the doors, but this is another adventure).


The results:

The left front.


The right front.


The rear right.

The rear left.

(Shhhh...silence please!).
The zero tolerance, door opening mechanism, pad.
(Rubber, teflon, grease).

25 February 2020

Having the electric windows fuse blown, (bad connection), and inspecting the control unit for the windows, found a wearied relay, just one of the six:


So, I found a used, as brand new,  similar, rear wiper relay, and replace it with perfect results.

The Syncro Heresy