S40 (New) Electrics : Using a Wiper motor for another purpose

[Sibbers2008]

I have picked up a front wiper motor from an S40 in a breakers yard, to use on a gadget I am building for my kids. I have got a transformer to take 240v AC down to 12v DC (max 3 amps) BUT I can't make the motor spin!

There are four terminals on the electrical connector (see attached photos) but one is blanked off (between the black cable and the small green/white cable on the right)
I am assuming that the Earth comes from the motor housing but as for the other wires I am lost and I must be being dumb as I can't even disconnect the electrical connector to try the blanked off terminal! please help !

Thanks

Sibbers2008

[ASt85]

According to the EWD the black wire is the negative earth return, the thicker green & white is the normal/fast wiper speed and the thinner green and white the intermittent positive connections.

I don't think the case is used as the earth connection.

Link to S40 Electrical Wiring Diagram pdf
https://qclt.com/html/volvo_ewd_us_e...x_3974202.html

[Sibbers2008]

Many thanks for your advice, as you said the EWD is pretty clear.

I have tried the combination you suggested on a car battery but still nothing. The car that the motor came from was not smashed up at the front, the linkage was all intact so I had no reason to believe that the motor was not working.

Could I have burnt out the motor by trying the wrong wiring combination or is it more likely that its a dud ?

Do you think the CEM is having an impact ?:

[PaddyB]

It's possible that simply applying volts isn't enough.

I wonder what the motor is expecting to see on the other wh-gn connector. From the picture it might be some kind of PWM signal

[andy_d]

As both signal leads come from the CEM, WITH a square wave signal, denoting Pulse Width Modulation,
Just stuffing 12vdc into it will do nothing.
the electronics IN the wiper motor unit are expecting a PWM signal to work them , not 12vdc.

IF you are only wanting the motor to run at a constant speed then taking the unit Apart
Removing the electronics board/boards and finding the + and - connectors to JUST the motor applying 12vdc to those will do what you want.

[Sibbers2008]

whats a PWM signal ??

so many abbreviations and yet page five of the wiring loom guide only describes the bleedin obvious !

[StatusRed]

Originally Posted by Sibbers2008

whats a PWM signal ??

so many abbreviations and yet page five of the wiring loom guide only describes the bleedin obvious !

Pulse Width Modulation, it's a way of controlling the amount of power sent to the electronics.

[Sibbers2008]

Thanks for the tip, yes, I just want a constant speed.
I've got nothing to lose so I might give it a go. i'm just surprised that the motor has in built complication.
Surely far better for Bosch to build more simple motors that can be transferable. These car designers really know how to complicate everything.
I really appreciate you all taking the time to respond to my thread.

[StatusRed]

Originally Posted by Sibbers2008

Thanks for the tip, yes, I just want a constant speed.
I've got nothing to lose so I might give it a go. i'm just surprised that the motor has in built complication.
Surely far better for Bosch to build more simple motors that can be transferable. These car designers really know how to complicate everything.
I really appreciate you all taking the time to respond to my thread.

I assume the PWM functionality is to alter the speed of the windscreen wipers

[andy_d]

but
by making the motor have Part of the electronics in it, they ensure you can Only buy the replacement from them at The price they set... its not That daft from there point of view,, add £2 worth of electronics in the unit charge £100 for a £20 motor" ,,