1974 240d W115 Intermittent Wiper Issue

[Techy-Mechy]

I have a 1974 W115 240D. The wipers work fine in low and high speed. The intermittent wiper doesn't work.

Does the wiper delay relay go bad on these cars or should I look at the switch? How does one test these to confirm what has gone bad?

Also, if the relay is bad, where does one get replacements?

Thanks for your help.

Dave

[JeffreyNMemphis]

Hi Dave,

The best way to test the relay is to swap it out for one that is known to be good. Do you have a subscription (Free) to Mercedes Electronic Parts Catalog (EPC)? You can look up the relay part number. If you are lucky, the same relay may be used elsewhere on the car to swap and test with.

Checking the wiper switch can probably be done with an Ohm meter?

[Techy-Mechy]

Hi,

No, I don't have the Mercedes electronics parts catalog. I'll look for it online. Of course, checking continuity is the best method for testing the switch (I should have thought of that).

I think that this relay is the only one like this on the car. I have my parts book that came with the car and determine where it may be located and potentially a part number.

Thanks for your reply!

Dave

[Techy-Mechy]

Oh my goodness, that Mercedes EPC has a steep learning curve! I spent about an hour fumbling around on the site while my 6 month old French Bull Dog was nibbling/yelping/jumping on me. I could not find the part. I think I found a relay on EBay, but the guy is really proud of them.

UGH..maybe I will call the dealer and/or email the guy on eBay.

Dave

[JeffreyNMemphis]

This may be what you are looking for? It is called a pulse sending unit.



I can help you get to this page on the EPC.