Hi,
I'm wondering if anyone has any tips for me on trying to figure out why my 850 ('95) wagon, rear wiper has just stopped working.
It makes a groaning sort of vibrating noise when turned on, but the arm on the window doesn't turn. Nothing is loose on the outside, so I thought I'd ask here for any tips before I open up the tailgate panel and see what's going on?
Thanks,
Alan.

 

sounds like the gears in the wiper motor are jammed up. Not uncommon - they are plastic and break (I've had to replace the headlight wiper motor and the windshield motor on my 850 at some point in time - all with the same symptom). Try seeing if you can manually assist the arm to swipe to unbind it. Otherwise you're due a trip to "Pick-a-part" to buy a new rear wiper motor.

 

So it is with all failed wiper motors. The gears don't have any teeth on 'em anymore. Car companies are too smart to sell just the gears for $2. Better to sell you the whole motor for $250.

 

So true FBP, but I have had the pleasure of replacing the plastic odometer gears on two different 850s...

 

Well, I tore open the back door tonight and took a look at the motor. The whole thing looks really clean for a 20 yr old car, but the big tube piece just vibrates (see photo) when the wiper is on. No movement. No amount of "helping" the wiper, or jiggling around seemed to help. Definitely the motor is working but not connecting somehow; I couldn't see anything loose or any cogs not engaging.....
Is it time for a replacement motor, or are there any other tricks I could try!
Thanks again for the help!
Alan.

 

You didn't believe us?

 

Ha ha!! LOL!
Well...nothing wrong with getting a second opinion (or in this case a fourth)!!!

OK, a new motor it is.

Thanks!!

 

Do I need the motor "only" (which I see some people selling) or the motor and linkage.... I guess I should just get everything?
Thanks,
Alan.

 

my money is on a failed plastic gear inside the housing, and I think the bet here is you can't find a replacement part for that gear... You can try opening up the case to look at the gears and see if there's some corrosion and try PB Blaster/clean, regrease etc but if that fails, its off to Pick-A-Part for you... Google on "Volvo Rear Wiper Motor Gear" and you'll find some posts in other forums from people who opened up the wiper gear case. Others who tried found that 1) their motor was good and 2) replacing the motor if bad is really expensive.

 

Well, I removed the wiper motor and linkage and saw a crack in the gear housing that is probably the issue.....so, time for a used wiper motor.

 

Well, I managed to get a used wiper motor (whole piece w/ linkage etc) on eBay for about $40 and just installed it and I'm good to go!
Thanks to everyone for all the advice!!