W140 Wiper Problems
 

I Have A 92 W140 And My Wipers Only Work When They Feel Like Working.i Tried Wiper Relays From 2 Other Cars And It Did The Same Thing. Also Tried A Different Stork On Column. Does Anyone Know Of More Conponents To This System Besides The Relay,motor Or Column Switch? Any Help Would Be Appreciated

Did you try both the wiper relay on top of the fuse box & the combination relay INSIDE the fuse box??

No, I Am Not Sure Which One Is The Combination Relay

Did you every find an answer? I have 93 300sd with a similar problem and with the suggestion to replace the relay. How does one test the relay?

Relay is black-box - no way to test it far as I know.

They're quite a few bucks from the dealer, but do show up from time-to-time on e-bay.

If there are problems with the combination relay, I would think that the problems would affect other systems besides the wipers - but maybe not.

I my case, the wiper relay was the issue. Sits on top of the fuse box lid - less than 5 minutes to R&R.

Board member Eddie A is parting a pair of 140s - I'll bet he has one or more wiper relays for sale. Good fellow to deal with - prompt shipper and reasonable prices.

Thanks to everyone for their help. I bought a new wiper relay from the Fast Lane and will be installing it later today.

w140 Wiper Relay
 

I bought a new relay from the Mercedes Shop.

When I replaced the original, I noticed that there was a small amount of corrosion on the connetors which I cleaned with a toothbrush.

Perhaps the relay itself is okay but I changed it anyway. I am keeping the old one as an emergency part because it worked 95% of the time and I commute about 200 miles each way.

Easy replacement: Open the fuse box lid, slide the relay toward you and lift. Finally pull out the connectors and inspect, etc.