Elec window query

[atwood]

Hi all...
Searched the threads, but can't find this one...
Pax side rear window goes down - but not up.... both switches - same problem. I decided it must be door motor/regulator related - extracted them and tested. All looks good on the regulator - lubrication OK... disconnected the motor, sure enough it runs in one direction - not the other. Here's where I get confused.... There are only two terminals, so I assume motor turns one way or the other depending on which terminal gets power. However - test light reveals permanent power to one terminal without any switch activity. Does this sound normal?

[Outback 1]

not sure about your test results but the symptoms are a common sign of motor failure

[mattg]

You motor should be fine it will be the teeth in the regulator they are made from soap I think.
About $50 from memory and 3 hours the first one then 45 minutes each time after that. Inbox me if you are quoted higher then that and I will hook you up with the right parts bloke.

Matt

[mattg]

If you have got that far take out the regulator remove the motor and plug it in. If it works sitting spinning I air fair chance it's not your motor.

[Outback 1]

I have replaced 2 for customers recently with exactly the same issue in both cases it was the motor

[atwood]

Thanks all.
Motor removed yesterday - yes it does "spin in air" but only in one direction!
I have just enough knowledge of electric motors to be dangerous, and I don't understand how it can spin one way and not the other. Am I right that by reversing the terminals it should reverse the direction of spin?
If you lot advise me that this is a common sympton of a dead motor - I will go and buy another.... but ... I think the interesting bit is the test light result on the wires. Should I be detecting power on one incoming wire, without pressing the switch?

Regulator and teeth look OK to me, plenty of lubrication and move freely.

Thanks all

[PhilipA]

Usually I have found in BMW and others that the switches go to ground and the wires to motor are usually live.
I was able to fix a Bosch BMW motor by opening it up and shaking all the used brush material out as the material had choked up the brush area.
Maybe worth a try in this case.
Regards Philip A

[sierrafery]

Thanks all.
Motor removed yesterday - yes it does "spin in air" but only in one direction!
I have just enough knowledge of electric motors to be dangerous, and I don't understand how it can spin one way and not the other. Am I right that by reversing the terminals it should reverse the direction of spin?
If you lot advise me that this is a common sympton of a dead motor - I will go and buy another.... but ... I think the interesting bit is the test light result on the wires. Should I be detecting power on one incoming wire, without pressing the switch?

Regulator and teeth look OK to me, plenty of lubrication and move freely.

Thanks all

There must be an electrical problem then cos the window up/down movement is achieved by reversing the polarity at the motor and there shouldn't be any voltage with switch in rest position

The rear windows operate by the switch providing both power and ground to the window motor. Pressing one side of
the switch provides a power and earth path to the window motor that allows the window motor to operate in one
direction. Pressing the other side of the switch reverses the power and earth, which allows the window motor to
operate in the opposite direction.

[atwood]

Excellent - you have confirmed how I thought it must work..... Tonight I need to put the door back together, pull out the other switch and start following wires... hopefully the other switch is the problem...... otherwise the customised bit of broom handle inside the door that's holding up the window might become a permanent fixture!
Regards and thanks

[atwood]

OK Problem solved.
For completeness..... I disconnected and removed the front switch, blew dust, dog hair and sundry out of all of the switches and wiring. Then I tested the motor wiring again, sure enough - I still have power without depressing the switch ... but now I have power on BOTH terminals. Turns out this is good..... when the switch is depressed it grounds one side or the other - turning the motor either way. Put it all back together and we are working perfectly... until the next issue....

[sierrafery]

OK Problem solved.
I still have power without depressing the switch ... but now I have power on BOTH terminals. Turns out this is good..... when the switch is depressed it grounds one side or the other - turning the motor either way.
I'm glad it's sorted and it works:)...watching the diagram too it confirms what you say, there must be voltage on both terminals with switch in rest position they should have said "the switch provides an earth path to the window motor" NOT "power and earth path"... it's not he first time when i find mistakes but in general the working principle is the same:cool: