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my rear wiper hasn't worked for a few months, but of course i'm only getting to this now that it is dumping rain out. i'm not positive, but i'm pretty sure that the rear wiper/washer worked when i got the wagon in sept. but if it did, it stopped working not long after that. perhaps right around when I installed a new stereo... hmmmm.
i've read other posts on here but i'm still not quite clear on how to read the symptoms. here's what i've got:
-neither intermitent nor continuous works at all. the washer also doesn't work.
-i pulled the tailgate trim off and the lingkage seems fine...grease and now clear seizing.
-the three wires going into the motor appear to have good connections, and the black one (ground?) on the motor body doesn't seem corroded.
-the fuse is fine
-when i turn the switch on to intermittent, and when I push the button for rear washer, i can hear the relay below the stereo making a noise.
-i took off the under-dash trim and checked the round-ish connector plug for the four wires coming out of steering colum (this suggested in one of the threads): the connection seems fine. if i unplug it the relay noise stops, so i assume that the connection is good.
any ideas on what to check next? some posts seemed to indicate a bad ground on the steering column could be a problem. others said something about the tailgate wiring, but i wasn't sure whether my symptoms ruled that our, or how to test for it. because the washer isn't working either, should i assume it is in wiring and not a bad wiper motor?
thanks!
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Go for the basics:
Measure for voltage at the connection to the motor with the rear wiper switched on. If no voltage, check the relay.
If it works, disconnect the linkage and try to operate the motor. It's one 10mm nut that you need to remove. If the motor runs when disconnected, then the linkage is your problem.
I've seen several 940s with the wiper shaft seized in the bushing that runs through the tailgate. Tailgate wiring is a regular problem in the 240 series, not so much in the 740/940 cars.
Good luck!
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hi,
thanks for the tips. i have checked the motor when it is disconnected from the linkage, and it still doesn't work. i'm not sure how to check the relay, however. i can hear it making a clicking sound once when the intermittent switch is thrown, so does that mean that the relay works, or could it still be broken? i don't have much experience with electrical things. i'm also not sure which is the rear wiper relay--the electrical page in the FAQ has a diagram but it isn't that clear. i was hoping to rule out a few things before buying a voltmeter, which i don't have.
my main question is: if the wiper motor doesn't work at all (when disconnected from the linkage) and the washer doesn't work either, what situation does that point to? most people on here either seemed to have a motor that worked but not in intermittent mode, or a motor that didn't work but a washer that did, etc.
thanks
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so i fixed the wiper, and I thought it was worth sharing the experience for any of you 945 owners who are facing a similar problem. What I discovered was not chronicalled in the forum here, and it might be easy to overlook if you take the tailgate apart and inspect the motor linkage.
first: I figured out that it was indeed a dead motor. 12v coming from the wiring harness, and no action with the motor. I picked up a used one and plugged it in. bingo! it worked.
then: after oiling up the linkage, even though it seemed to move freely already, i attached it to the motor. turning on the motor, it rotated for about one third of a turn and then stopped cold. huh? this couldn't be the normal range of motion for the wiper--it didn't even make a full sweep of the rear window.
I inspected the linkage. it moved fine, but could physically only go for a short distance before one of the metal connecting arms hit against a one of the rivets that holds the parts together and allows the linkage to pivot (it is more or less like the metal linkage attached to the wheels of an old steam engine: a continuous rotation at the motor is transformed into a 180 degree back-and-forth rotation at the shaft of ther wiper). I realized that it would be physically impossible for this linkage to move the wiper in the proper range of motion. instead it hit a stop and couldn't move any further, inhibiting the wiper motor's movement.
after scratching my head for a while I went to the dealer and looked at the parts diagram to see if somehow I was missing something from the assembly. I wasn't, but what I discovered was that the linkage itself had somehow gotten inverted so that the little connecting rod, that has a pivot on either end and in the middle has the shaft that protrudes out of the back window, connecting to the wiper blade, was now upside down. The only way to get it back in the right position was to pry with a screw driver so that the short connecting arms cleared over the rivet that they were hitting against, stopping their free motion. It is hard to explain how this looks in words but if you saw an image, you'd understand.
In any event, I cant' fathom how it got flipped over by the wiper motor, when it took a lot of force on a big screw driver to get it back. and it appears that once it was inverted, and the range of motion was inhibited, the old motor just burned out. so how could it have ended up that way? it is a mystery, but the important thing is to *** check this out if your wiper motor is burned out.*** if I had left it attached to the new motor it would've burned out too.
now it works like a charm. if somebody has a diagram of the linkage and they want to post it I'd be happy to point out what I'm talking about, FYI.
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Congrats. Now to your rear washer problem. You've probably already figured out that the rear washer pump is located with the windshield washer pump at the bottom of the reservoir in the engine compartment. Start with a quick check of fuse 14. You can then try to listen for or feel the pump running, but once pressure has built up it won't be making much noise.
The most common failure mode for the rear washer is the anti-siphon check valve in the hose and it's located at the rear, just above the right tail lamp assembly. As it's easy to check, I'd start diagnosis there. FYI, the rear washer hose runs along in the right rocker sill then up over the rear wheel well and up the rear pillar to the washer head. Remove the interior plastic cover for the tail lamp assembly. Reach in the pillar channel and grope around until you find the rubber washer hose. Pull it down a bit if needed to reveal the plastic check valve. Disconnect the supply hose from the check valve. Point it out the back of the car or into a bucket and try the rear washer. Odds are it will pump just fine. Typically the diaphragms in these valves become gummy and block the flow. Replacements are available from Volvo or from web sources like FCP Groton. It's a good idea to replace the front one at the same time (located where the lines branch off at the rear of the hood). Note that the rear check valve is different from the front. The rear is an "L" shape (or an "F" shape), the front a "T" shape.
If no fluid comes out then it's back to the reservoir and the washer pump. You can pull off some hoses and the freeze chamber to see if there are blockages there, but I doubt you'll find anything. This would now be a good time to get yourself a cheap multi-meter and start learning how to diagnose electrical problems. For your benefit I'll go into a bit more detail than we normally would here. A digital meter is a good investment and can be had for under $20 if you shop around, but a $10 analogue meter will do in a pinch. Remove the connector on the rear washer pump. The rear washer pump connector will have a blue/yellow wire and a black wire in it (if you find a blue/red wire you're on the wrong pump). Now check for power to the pump. Start by setting the meter on the next higher DC scale above 14 volts. Then, with the red meter probe on the blue/yellow terminal and the black probe on a bare metal point on the chassis (or engine block), have someone turn on the ignition and operate the rear washer. If you see voltage then it's either a bad pump or a bad connection of the washer motor connector black wire to the chassis ground point (behind the pump/headlight area). Otherwise, if no power is getting to the connector then it's either a problem at the relay (rightmost in the rear row) or a problem at the wiper stalk. Diagnosis gets a bit more detailed at this point, so I'll leave it there for now.
--
Dave -940's, prev 740/240/140/120 You'd think I'd have learned by now
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Hmm, sounds like small urchins to me. Many moons ago, I had a similar scenario except the wiper was not quite sitting correctly. It seems my young (4?) son & heir had used the wiper to haul himself up onto the bumper thereby twisting the linkage out of whack. Perhaps something like this occurred before you got the car & the PO had wrested it into a semblance of normalcy appearance-wise. I doubt the motor would do this to the linkage without outside help. Your theory as to the fried motor sounds valid.
Anyway, the wiper & spritzer are two separate circuits so you probably want to check the pump motor for the rear washer, see if it is pumping and go from there.
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thanks rjk2 and dave. I actually learned form the friend I got the car from that some vandal had twisted the wiper, and she twisted it back to the normal position but never fixed it. So that's the source of the linkage problem.
as for the sprayer pump, I wasn't hearing any sound from it and without wanting to borrow a voltmeter again, I tried a simple test--I just switched the plugs with the front washer pump, which does work just fine. And the wires from the rear powered the front pump, so it seems like the pump itself is bad. the autopart store has an aftermarket one for twenty bucks.
and my dad just gave me a voltmeter that he wasn't using. so in the future I'll be able to diagnose things better!
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