HELP PLEASE. Strange electrical problem

[MikeVernon]

The screenwasher pump on my SLK has stopped working after the car has been unused for a long time. The pump motor if fine, but the electrical feed to it has a strange problem. I've unplugged the two wires which connect to the motor. One is the earth, and the other has a voltage reading of 4.31v all the time, whether the ignition swich is on or off! Operating the screenwasher control makes no difference to this reading.

Any ideas? Does the screenwasher circuit contain a relay? Does the feed to the pump motor come directly from the switch on the steering column? I'm thinking that if it does then I can connect a wire directly from the switch to the motor to eliminate any wiring fault between the two.

 

[television]

You just cannot go adding wires as these things have ECUs that control things.

Give me a reminder later in tonight and I will see what I can find

 

[MikeVernon]

Hi Chocolate
That's what I'm trying to find out - is the screenwasher contolled by some kind of electronic module or does the power come directly from the switch? I realise that the same switch makes the wipers run for a few seconds as well as the pump, but the switch could still supply power directly. The wipers do operate when the switch is pushed, so presumably the switch itself is ok.

 

[MikeVernon]

Hi Malcolm
Did you manage to find out anything? I need to know where the feed to the screenwasher pump motor comes from. The wire is red/green.

 

[television]

Hi Malcolm
Did you manage to find out anything? I need to know where the feed to the screenwasher pump motor comes from. The wire is red/green.

I forgot,,, please remind me this evening by just posting here and I will see it

 

[MikeVernon]

Hi Malcolm

Here is your reminder as requested!

Thanks.

Mike

 

[television]

Please go to your other post and I can send the diagram to you