REPAIRING THE HEADLAMP WIPER MOTOR:
Having taken the complete wiper motor out yesterday, I spent a bit of time on the internet last night and found a SAAB 9000 owners' website where someone had detailed photos of wiper motor internals, you may have to copy and paste this into the 'address' feature on you browser, but it's definitely worth a look!
http://www.saab9000.com/procedures/e...wiperepair.php
The V40 headlamp wiper motor is almost identical to the one on that website - except the one in the V40 has a straight rack as opposed to the curved rack on the older SAAB item. Both units manufactured by Bosch.
If you work slowly and carefully you can 'spring' the small plastic snap hooks on the plastic casing without damaging them - I got lucky and only managed to break one of them. Tease the flat cover away with a small flat bladed screwdriver. Nothing should come out, so don't worry.
Having made lots of alignment marks (for re-assembly) with a fine permanent marker on the rack, gears and metal plate, I proceeded to push the spindle back into the casing a bit, then removed the rack, plate and two gears - leave the worm gear in place. I got the small electric motor out by carefully levering it up at its back face. It's not soldered in, the two electrical tabs on the motor slip into contacts held within the plastic casing. Its shaft has a 'D' shaped cross section that locates in the plastic worm gear.
We need to clean the gaps between the commutators, so the next step is to open up the small electric motor itself. I damaged the two small tabs on the metal motor casing trying to open them out but don't worry about that - the motor is held so that it won't come apart anyway. Very carefully work between the plastic cap and metal casing and slowly pull the plastic cap away. Be aware that the two brushes are in the plastic cap so be very careful as you remove the cap. It is a good idea to pull on the motor shaft itself to prevent damage to the thin strips that hold the brushes.
The brushes were fine - plenty of meat left and no damage. The commutators were shiny and no signs of burning etc but the gaps between them were filled up with carbon. Carefully scrape that out with the point of a craft knife blade. Give the commutators a clean with a bit of really fine wet and dry (used dry - and wipe around the commutators - not along their length) then a wipe with some electrical contact cleaner. (I didn't have any - so I sprayed a little brake cleaner on a small bit of cloth and used that instead).
Work carefully on re-assembly. There is a little bump on the plastic cap which locates in the metal motor can for alignment, make sure you get that in position. I'm confident that it will stop the cap spinning relative to the can, another reason for not being overly concerned about damaging the two folded metal tabs on the motor casing. You may need to rotate the motor a little to be sure that its D shaped shaft locates properly into the end of the plastic worm gear.
Put everything back together - using the alignment marks you made before dis-assembly as a reference.
We're lucky on the V40 - we can test the wiper motor works before re-installing - just reconnect the plug and socket and get a helper to operate the windscreen wash-wipe while you hold and watch the headlamp wipe motor. (I wrapped a bit of tape around the wiper shaft to make a flag - so I could check that it was actually operating properly).
All good and well, so re-install the motor, headlamp, bumper and indicator, also replace the cover under the bumper. Operate the headlamp wipers a few times so that you can be sure the shaft is in the parked position before refitting the wiper arm.
JOB DONE!
If you decide to do this job yourself, print these posts out if you think they will help and go to that SAAB 9000 website too and print the article out. The chap that wrote that article gives an address for a company that can supply the small electrical motor on its own if you need one - rather than scrapping an otherwise service-able set of wiper mechanics.