240 Wiper Wierdness

Noticed the wipers on my 1992 240 are acting up a bit. Read through the CleanFlameTrap write up on wipers and am still a bit puzzled. Here's a rundown of the symptoms:

1. Wipers operate normally on slow and fast speeds
2. On the interval setting, wipers just operate normally on slow
3. When turning the wipers off, wipers will keep running for a few sweeps. Sometimes they will turn off as normal, but usually stay running.
4. When the wipers do eventually stop, they stop in the normal park position.

So with all that, am I looking at a bum relay, dirty motor contacts or both?

Thanks

I would check and clean all the grounds at the motor including the contacts under the plate. Had this problem once, turned out to be bad grounds.

^^

Agreed. First thing I'd do is pull the cover and clean the contact point on the back of it. If that doesn't do it, I'd look over my notes on where to poke the test light to actually diagnose the trouble.

Thread jack...

are the wipers in 240's all noisy? my cables seem tight, not overly tight but they seem to make a lot of noise

hope you get the weirdness sorted esp since we are about to get dumped on again.

Noisy as in clunk clunk? Disconnect the crank from the motor shaft (10mm wrench) and operate the wipers by hand. Any resistance is likely to be found in drive bushings.

Grinding noise from motor? Magnets break loose from the motor housing as it rusts.





http://cleanflametrap.com/wiper.html

I suspected the bushings, but have had poor luck in finding replacements.

Will keep poking around though

thanks for the tips

Update.

Pulled off the cover and had a look. Found really badly corroded contacts.



Gave them a quick spritz of contact cleaner. Overall, the wipers work much better. They seem faster and smoother.

Also return to the park position immediately when switched off. Still no interval wipers though.

Good enough for now though. I've got a spare motor in my parts bin I can swap in when I get some more time

Thanks.

Don't know if this was true all the way to 1993, but on the older 240s, the interval relay is located directly in the drip path of a water leak from the corner of the windshield. (I hope someone won the "bullseye" award for that.) Pop the relay cover, you might be able to clean out corrosion from there also. And when you reinstall, flip a U-turn into the last few inches of wiring harness so that the relay connections (and thus water entry point) faces down instead of up.

Yeah, the relay is still in the same spot, behind the dead pedal bracket. I usually move the relay so it's tucked up behind the cluster. The older 1235067 part number relay works fine on the later cars. Just a superceded part number.