1990 245DL

Arg, I'm playing whack-a-mole with failing systems.

First it was no wipers at all. Found a hole rusted in the motor so I replaced the motor with a used one and that fixed that problem (for a while). Then there were no rear electrics, so I replaced the wiring harnesses in the tailgate. Then the engine started to stall under mysterious circumstances and I'm still working on that problem. But now my front wipers have gone out again.

The wipers suddenly quit working on the way to work a few weeks back. They worked fine when I left that day so I opted to wait for it to happen again. Same deal happened again two Fridays ago and came back on abruptly on my return trip home. Now it has happened again and but they have not come back for more than three days now.

I've searched the archives and found references to water on the relays, but nothing else. I've checked the connections at the motor and dug out the blue and black relays (both were dry with no evidence of corrosion on the connectors) I've even swapped the relays for some spares and it has not changed anything. There's no evidence water is getting in back there.

My rear wipers work fine, front wiper are dead on full and on intermittent. I can probably expect them to suddenly start working again soon, but I doubt it will be during the next rainstorm. I've not dug out the DMM yet, and I'm not sure the spare relay I tried was appropriate for the system.

Do these symptoms sound familiar?

Basic question that I assume you've already checked, but to rule it out - fuses?

Well, I checked it for integrity and it was unbroken.
But I did not spin it to break any corrosion.
A few spins and BAM! works again.
Thanks for telling me to check the obvious.

However...
It doesn't seem to stop in the correct place now. Comes to rest about 1/4 way up the windshield. That's a new problem. Sweeps the whole window and dips down to the cowl, but returns to the 1/4 mark when it stops. Parks lower when in intermittent... weird.

One important thing to check on all the motors is the ground under the mounting bolt. They do get all eaten up and you need a good solid ground. I added a ground wire from the engine ground strap to reduce the corrosion problem.

Your pick your part motor has issues. I had the same types of wiper problems going down the used wiper motor path. To the tune of four or five motors over a couple of years in fact. Had them that stopped at the top, then at the bottom, then in the middle. Had them with no intermittent, no fast speed, and my all time favorite no speed at all. The no speed was at night in a hard as heck rain storm to boot. The best of those motors was far the worst looking of the lot, the one that died all together looked almost new. The common thread with them was they were all out of donor cars. Four of them did work at first and then developed issues later. One of them started out exactly like yours is doing now, stopped sort of in the middle. Wait for it, there are more places it will come to rest in the future.

With used motors you are most likely headed into a cycle of changing motors.

What finally solved all my problems was a lifetime warranty rebuilt motor. It did take four of those before I got one that worked. That was the crappy workmanship by whoever rebuilt the motors, two were dead right out of the box. Wipers have not been an issue on the front for over a couple of years now and that is sure nice.

Knowing what I know now, I would have purchased a brand new motor right off the back.

Good Luck,

Paul