1978 SC electric window question please

[100702mark]

Since getting the car the passenger electric window has never worked. I've pulled the door apart today to check the obvious loose wire etc but there is nothing obvious. I'm a bit puzzled and wondered if I can ask a question of the knowledgeable please. There are two wires going to the window motor. With the ingnition switched on both are live. When I press the switch to wind the window up or down, the flow is interrupted and the live feed stops. Is this correct or does it suggest there is a wrong connection on the switch.

It would also be really helpful if someone could gently prize out the passenger door switch and post a photo of which colour wire goes on which spade please.

Anty help gratefully received.

Many thanks


Mark

[Nick Moss]

Does the window operate from the driver's side?

[100702mark]

Drivers window works fine but passenger window won't work using passenger switch or the switch on drivers side.

Many thanks

Mar

[Chris993C2]

Although I'm not familiar with SC window wiring, in general electric window motors (and central locking solenoids too, for that matter) fall into one of two camps:

i) rest-on-ground: both wires to the window motor rest at ground. To drive the motor, one of these is switched live (12v) whilst the other is held at ground. To reverse the motor, the other wire is switched live.

ii) rest-on-live: both wires rest on live. To drive the motor, one wire is switched to ground whilst the other is held live (and vice versa).

From your description, it sounds like the SC has (ii) rest-on-live.

You say that both wires are live (with the ignition on), and that operating a window switch "interrupts" one of the live feeds - but (crucially) do you know if the "interrupted" wire is actually connected to ground? If not (ground wire not connected on drivers' door (passenger) switch, bad earth point etc) then there is no circuit, and nothing will happen...

[Nick Moss]

Drivers window works fine but passenger window won't work using passenger switch or the switch on drivers side.

Many thanks

Mar

Your problem is more likely to be on the driver's side then.

[PeterK]

You say 2 wires going to the motor. Is there also a ground wire connected (IIRC there should be) ?

[T911UK]

Window switches are pretty simple when you know how they are wired!

Top single spade is red 12 volts+ this is looped to bottom right spade

Bottom left spade is brown earth

Middle 2 spades are 12 volt up and down

The motor has 2 wires, fed from the 2 centre spades on the switch

Motors do pack up or seize, put 12 volts directly onto the motor without the wires attached to check its ok, then check the switch, the wiring and even the relay

[100702mark]

Thanks that's brilliant and one to keep in my file for future ref.

Mark

[100702mark]

Thanks all, all sorted now, it was a broken motor and failed switch.

Mark

[100702mark]

I've made some progress here but still not quite there and I wonder if anyone can help. I've had a good look at the wiring diagrams and can't quite work out logically what's happening.

In summary.
Passenger electric window when operated from drivers side switch now works fine up and down.
However when using passenger switch nothing happens but it does blow the 25 amp fuse. Switch changed, no difference. Tester shows live feed ok, earth ok, and both live outputs working and go off when switch flicked.

Thanks

Mark