Thank you for you editing Pizzaguy, I understand about the difficulty of reading some of this stuff as I sit here with my readers perched on my nose! Most of the forums I have used compact everything so I have become accustomed to not putting breaks in.

As to the service manual, I have bought about a million over the years and always seem to have an issue that is poorly covered. Also, with this series of issues I just started off with the basics of diagnostics, a skill that is rapidly disappearing. My guess is much further diagnosis on this pump/security module will require MB's computer system. I will take a look at the manual and wiring diagram, but by back probing all the wires back there I'm not getting any trigger voltage in the 12V range, just less than 1V stuff, so I think I'm out of my league technology wise.

I do have an Ezsoft MB scanner and when I pretend to be an SLK it doesn't find a problem. (We also have an E350) I'm hopeful that drying things out and staying on top of those drains will prevent some of these issues going forward.

It's nice to have all of these features that modern cars offer, but it adds so many levels of complexity to repairs. As I type this a 53 Chevy just pulled up (I'm at MCDONALD'S waiting for Napa to open) with the old stovebolt and 3 on the tree, remember when you could fix just about anything with some baling wire and tape?

Thanks for any and all help, forums and shared experience is such a great help for those of us who try to keep cars on the road and away from dealerships!