Bad earth?

[Moomoo]

Yesterday the passenger side front window refused to go up on my 91, 240 ,when either switch was used. Then it did go up but slowly.
Also , occasionally the same door lock doesn’t unlock first time . A retry usually opens it. Even first time the button comes up , just not fully.

Bad earth?

[Othen]

Originally Posted by Moomoo

Yesterday the passenger side front window refused to go up on my 91, 240 ,when either switch was used. Then it did go up but slowly.
Also , occasionally the same door lock doesn’t unlock first time . A retry usually opens it. Even first time the button comes up , just not fully.

Bad earth?

... or a bad 12v supply, with electricity is sort of has to be either the door in or the door out :-).

The common -ve return is most likely. The window winder motor probably has its -ve return (earth) via the chassis, so test the impedance between that and the door, then the same to a good conductor on the chassis. If they are appreciably different then that will be the issue.

If it isn't that check the supply voltage to the motor, try moving the door around a bit as you do so. Usually the fault will be the flexible bit where the wires go from the chassis to the door.

Good fortune.

Alan

[Moomoo]

Ta bud. Super comprehensive answer!