News:

www.W116.org - The #1 resource for our W116! Established 2004

Main Menu

Window regulatot

Started by marku, 29 July 2020, 12:41 PM

marku

How would you test the motor for proper function? Took it off the car because regulator wasn't working and found motor gearbox solid with dry grease. All clean but can't see how motor works as there are only 2 wires up and down. Is it DC as understand you can change polarity to reverse not AC?
1974 450SE silver green/bamboo velour/green vinyl roof

ptashek

Quote from: marku on 29 July 2020, 12:41 PM
How would you test the motor for proper function? Took it off the car because regulator wasn't working and found motor gearbox solid with dry grease. All clean but can't see how motor works as there are only 2 wires up and down. Is it DC as understand you can change polarity to reverse not AC?

Yes. The polarity is reversed at the switch.
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE

marku

Yes but does not answer how I test the motor alone? There is only the 2 wires which are up and down. I assume that with polarity reversal that the 2 wires would change positive/negative but there is no ground for the motor alone.
1974 450SE silver green/bamboo velour/green vinyl roof

ptashek

Quote from: marku on 30 July 2020, 07:38 AM
Yes but does not answer how I test the motor alone? There is only the 2 wires which are up and down. I assume that with polarity reversal that the 2 wires would change positive/negative but there is no ground for the motor alone.

It's a DC motor, if you give it +12V on one lead and ground on the other, it'll spin in one direction. Reverse, and it'll spin in the other.
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE

marku

That's what I thought but it doesn't. It just hums and from that I presume it is no more. It is an ex-motor. Rotor turns freely so it is not that. Will re-assemble until I get round to replacing. Thanks for advice.
1974 450SE silver green/bamboo velour/green vinyl roof

ptashek

Quote from: marku on 31 July 2020, 07:11 AM
That's what I thought but it doesn't. It just hums and from that I presume it is no more. It is an ex-motor. Rotor turns freely so it is not that. Will re-assemble until I get round to replacing. Thanks for advice.

Could be as simple as worn out brushes. Those motors are perfectly rebuildable, unless the windings are shot.
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE

marku

Maybe but how do you get the pvc cover off complete.
1974 450SE silver green/bamboo velour/green vinyl roof

ptashek

Quote from: marku on 02 August 2020, 10:11 AM
Maybe but how do you get the pvc cover off complete.

They are epoxy potted from the top if memory serves. It needs some careful prying around, but should come off.
I've looked at my resto pics as I remember having a couple of the motors in a disassembled state, but can't find them anymore.
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE

marku

1974 450SE silver green/bamboo velour/green vinyl roof