Although I don’t own this model I want to thank you for taking the tine to film and upload. High five bro!

Great work thank you for the details much appreciated keep them coming my friend 🤙

If it isn't the OVP relay the high idle problem might be that cursed air fuel ratio potentiometer that has wear parts in it. It was the issue with both my '91 560SEC's and 420SEL high idle problem. If you go ahead and diagnose and even fix that please do post a video on it. It will be very helpful to owners who maybe stonewalled with parts replacement process of the idle speed valve ($$$) and idle speed control module that does not give the desired resolution. Although I do not own a K-Jetronic car anymore this video was helpful in the case I ever buy another again. OVPs were once relatively inexpensive but not anymore. 😢

how do you bench test this model of OVP relay with a multimeter? What pins do I check, which one is Hot? Ground? and what should my readings be on the other 2 pins?

I have a few from when I had my w202 which I miss

Nice job!

There is a relay inside this relay, and cooper contacts inside should be refubrished.

thats not rust. it is soldering flux. someone soldered long time ago (possibly factory repair to not scrap)