940 Headlamp Wipers. Overhaul??

[Ian21401]

1992 940 estate. Headlamp wiper problems. Having trawled this site it appears that these things cause problems with the main faults being: 1) not self parking correctly or 2) "freezing" in any position and then "creeping" intermittently or 3) simply siezing completely.
I've owned the car since 2005 and they have worked fine until last year when the nearside one refused to self park. I removed the headlamp complete with the wiper motor and removed the back of the motor so exposing a gear and an operating arm. I removed them and gave them and the inside of the casing a clean up. I was loathe to attempt to dismantle any further as I wasn't sure if I would cause irreversible damage or at best not be able to reassemble it. In any case, after a successful bench test it seemed to behave.
Now the offside wiper is misbehaving. It initially was refusing to self park but has now frozen and moves ocassionally upon ignition switch on.
I note from previous threads (all be it most of them quite old) that there are 3 wires (earth,live +12v and intermittent live +12v). There is also reference to a "Self Park Disc", a "Thermo Disc Cutout", a "Flat Metallic/Plastic Fuse" and a "Diode". Are all of these present in every motor or are they various parts of different types of motor depending upon model of car?
As I suspect that good used motors are probably quite rare now and in any case will cost money I would like to have a go at overhauling mine.
Is there anyone able to provide a step by step "how to" to do this or point me to somewhere where I could find the relevant information.
I'm aware that there is an option to simply remove the things but I would prefer not to do this. Apart from the obvious of cleaning the lights when in foul weather behind spray creating HGVs I found them very useful a couple of winters ago whilst driving in heavily falling snow. The snow was building up on the headlamps and dimming the lights considerably. A quick wipe of the headlamps cleared the snow from them.
Has anyone successfully stripped and overhauled a motor before please?

[wrinkles]

It would be interesting to know hoe they operate do the just work with the windscreen washers or do they work on their own because I don't think mine work either I did hear somewhere that they only work every 5th go on the screen washers but I don't know for sure. I will have to take them apart when the weather is a bit better.

[barkster1971]

I got mine working only for the other side to fail! They are packed with grease so not worth taking apart. Put new blades in and clean the connectors. I would replace them but the screws are normally rusted to hell and can be a pain to get off the headlights.
You need to get the correct side as they can't be swapped. The should work when you press the stalk for screen wash.

[wrinkles]

Mine don't work will take to bits when I get time.

[Alasdair1]

Mine are very rarely in the same position. Weird thing is they seem to move by themselves. Even if I don't use the screenwash they will always be In a different position next time I look but they never seem to be in sinc.

Alasdair

[bob12]

You might find these 2 links helpful that I have copied from a previous post of mine.

"You might find these 2 articles helpful if you are going to get down and dirty!

One is on here by Jod T5:

http://www.volvoforums.org.uk/showthread.php?t=51146

and the other is on the Saab 9000:

http://www.saab9000.com/procedures/e...wiperepair.php

Bob. "

[Ian21401]

1) On the 940 they operate whenever the windscreen washers are operated and the blades are supposed to park on the outside of the respective headlamp.
I understand that the "every 5th operation" of the windscreen washer is on later models. My daughter's V50 does that. It doesn't have any blades. A nozzle pops up from the front valance and throws a lot of high pressure fluid at the headlamp. The handbook states that the "every 5th time" is to conserve washer fluid.
2) Yes. The screws holding the wiper motor bracket to the underside of the headlamp unit are very badly corroded and will be almost impossible to remove without damage, requiring replacement screws, but it is possible to access the motor without removing it from the headlamp. Obviously the headlamp must first be removed from the car.

[855 tdi]

I'm amazed you had 2 working, my dads 855s didn't work, my 855s didn't work, the low mileage v70 i bought for bits didn't work, my 745s don't do anything at all. To my amazement the 945 ive bought for parts has one working headlight wiper. I think most peoples don't work on the older cars now and a lot of people just take them off as like me they cant be bothered with them, even if they don't work i think a Volvo looks wrong without any.

[bob12]

I see that the above link to the Saab site no longer works. Just go to www.saab9000.com and use the search button as it's still there.

[Ian21401]

Each of those links looks very helpful. Domestic circumstances permitting I'll have a go tomorrow. The knowledge base of this forum is amazing. Thanks again.