Help! The intermittent wiper setting on my 1998 E320 4-Matic does not function properly. When the combination switch is in the intermittent setting the wipers function as if the combination switch was on the slow setting. My car does not have the rain sensor option. I cannot locate the relay or other control that governs the intermittent wiper function. Can anyone tell me where the relay is located? Has anyone else had this problem and how did they fix it? Could the problem be with the wiring or the combination switch?

I have heard that if the combination switch is set to intermittent and the wipers wipe at the slow speed then the problem is with the combination switch. Can anyone verify this?

My mechanic is an independent and does not have WIS. His diagnostic software was unable to help him locate the components that control the intermittent function. (He said that there were a number of components.)

Any help would be appreciated. Thanks!

My MB is older than yours ('84). I had a non funtioning intermittant wiper too. Just fast and slow. That's it. I replaced the combination switch too. Did not solve the problem. I changed out the wiper relay and now works like new now.

Sorry, I do not have any CD shop manual info on your model. I found my relay inside the fuse box next to the fuel pump relay.
Good luck..

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Thanks for your response. I have been informed that my car uses a computer called a signal adaptation module (SAM) to control the wipers, and the SAM has diagnostic capabilities. I am not aware of how to access these capabilities however. Does anyone know how to use the diagnostic capabilities of the SAM?

A dedicated MB scanner is required to access that computer.

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