How can I test a wiper motor to make sure it is actually bad before purchasing a replacement?

Thanks
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1992 240GL, 1985 240DL Wagon, 1983 240DL

If the intermittent relay is bad, will that stop all motor function?

Disconnect it at the linkage and try running it-- the dimming you describe sounds like it is mechanically impeded right now.

Good luck!

Though you do not say specifically, I assume that the wiper does nothing with the wiper stalk in any position. Correct?

Did you check the fuse? In the 1984's, the wiper motor is one the same fuse as the horn and the washer pump. I've had a few times where a fuse looks OK but on attemped removal the metal strip falls in two. Tricky rascals!

Fuse OK? Next check for power at the plug. The motor does not ground through the harness. There is a separate connection to the firewall via a brass piece from motor to under a mounting bolt which is invisible under that black gooey sealant. (It is rope caulk, BTW)

Looking at my 1984 wiring diagram book, there are four wires. One, yellow, is hot all the time from fuse #1. You should get 12v there, with the key in.

Next is a brown wire, which is hot in speed #1. From the diagram it looks like if you apply 12v+ there the motor should run.

Next wire is green which is hot in position #2.

Last is a White/black wire that is in the circuit during the parking sweep.

Actually, some motor failures are visible. I had a 1986 motor go out, and found that in the housing where it is tucked in close to the firewall padding, there was a dime-sized hole and somthing rattling around inside.

I believe that motor is the same from 1975 to at least 1988 and maybe newer. The only change I know of is in that ground connection. That makes the motor a junk-yard or re-cycle item, not an after-market item. I believe that used but good Volvo parts usually trump new aftermarket parts in many cases.

There is a relay in the intermittent wiper setting. There are six wires to it, and it is located above the driver's left toe.

Good Luck,

Bob

:>)

Wiper stalk does nothing in either position, don't even hear the motor trying to do anything, although I do see a dimming of the idiot lights when I move the stalk.

Horn works, fuse is ok.

I am thinking this may be something with the wiper linkage/transmission assembly behind the glovebox.

Remember, all was well until the passenger wiper got out of sync and the driver side wiper crashed against it. So I am hoping the motor may still be good, but just locked somehow because of the wiper linkage-the driver wiper is locked in the up position, so I think that may be the problem- somehow something came apart causing the whole assembly to jam up.
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1992 240GL, 1985 240DL Wagon, 1983 240DL

I was chasing a wiper motor problem on my 83 a couple years ago. After switching out the motor I eventually found the yellow wire disconnected from the fuse panel. Look at the connections to the fuse panel the yellow on #1. The ground is also the most suspect from what I've read in the past.