Pesky windscreen wiper problem on Golf

[JDLDIY]

Hi there, anyone any good at auto electrics? I've got a rear wiper that isn't working on a MK 4 Golf. I've established that there is power going to the wiper, but there's still no action. I want to establish that it is definitely the wiper that's knackered before I go and replace it only to find it's some relay somewhere, so it's some pointers in testing the wiper motor that I could do with.

Many thanks

JD

 

[jonnyfishing]

At what point did you test for power,was it the switch or the motor ?


If you can't get a live feed at the motor,look to the wiring at the point where it comes from the roof to the hatchback.Look inside the rubber trunking for broken wire/s. (usual fault on a lot of hatchbacks)

To test the motor,remove it and test it across your battery using a suitably rated fuse. 15A should do it.

 

[JDLDIY]

To test the motor,remove it and test it across your battery using a suitably rated fuse. 15A should do it.

Hi there, yes this is the bit I want to do but is where I am struggling. the motor has 4 connections to it. 1 is earth which I have checked. 2 is to the wiper solenoid (located in a front footwell) 3 is also to this solenoid 4 Is to the fusebox and is connected and carries 12v to the wiper motor connection where I have tested it. So what does the wiper solenoid do when there is live 12v always at the wiper motor? Presumably it sends a low voltage/current signal to the wiper motor which in turn opens a circuit to allow the current from the permanent 12v live to power the motor? Christ this would have taken me 2 mins to diagnose on an old car!

So, how do I connect it directly to a car battery? Which terminals do I use? The connections to the motor are via a little black plastic box attached to the moror's gearing housing, what does that do? Presumably that works in tandem with the wiper solenoid to open up the power circuit? The 2 connections from the solenoid are therefore 1 for permanently on and 2 for the wash and wipe (quick squeeze of the indicator)? If it steps down the voltage/current for any reason I would hate to connect the motor up to a battery and blow the whole thing when I'm trying to test it!

Having taken the armature out of it's housing I found that it has some abrasioons on the metal rounded surfaces. Would that be a manufacturing error and considered normal or could that point to the problem I'm having?

Cheers.

JD

 

[jonnyfishing]

JD

I would guess that the four wires are..one for wash/wipe,one for on/off,one earth and one for park

The permanent live is the one that takes the wiper to park position after you switch it off.

You know which is earth. (is it grounded o.k ?)

I would run a fused length of wire from the battery and touch each of the other two terminals in turn ,see what happens,if no response,look to the motor .

 

[JDLDIY]

I would guess that the four wires are..one for wash/wipe,one for on/off,one earth and one for park

AAhhhh!!!!!!!!! Of course! Thanks for that, yes of course that must be the way it's handled. That makes sense so when I next get my hands on the car I'll give that a go.

So what do you think the black box (that the 4 connections go into on the motor) does? It has a small printed circuit board inside.

Cheers, many thanks jonnyfishing

JD

 

[jonnyfishing]

JD

Distributes and or regulates current?,don't know really, makes it look complicated and expensive to people like us so you have to buy new.Bet you can't just buy the circuit board if it goes faulty.

Cheers

 

[Luke]

Hey there,

If you can get me a picture of the circuit board I will diagnose what it is and if there is a fault on the board.

Have you run a continuity test on your grounding? There are no connections shorting or going open circuit? Does the motor get hot when you run 12v through it?

Remember, if you want to test if 12v is getting to the motor, you must have the required steering wheel stalk up or the right 'knob' turned.

Regards,

Luke.

 

[breezer]

If you can get me a picture of the circuit board I will diagnose what it is and if there is a fault on the board.

 

[Luke]

What's up, Boss... you seem to have gone through a flurry of facial expressions?

EDIT: Aha.. what I meant was - I can most probably tell what the board does by looking at the components on the board.