[Dave2302]

The car has sat without being started at most 3 months. 81k miles....no mechanical issues. While I was putting everything together I noticed this disconnected Pink wire in the vicinity of the ignition switch.....no clue where it connects to. Seems to connect with a wire harness going toward back of instrument panel. The car will not start.....no crank, no ignition, no sound. Battery is fully charged....lights, windows, fans, everything kicks in....

I don't recall ever seeing that wire, I think it was added by some previous owner for whatever accessory etc.

Back to the issue, (see highlights in quote) ....

If you mean the Cooling Fan then then your issue is almost certainly K40 Even if not Cooling Fan, the K40 is certainly a very worthy suspect

I see this a lot, solder joints are notorious for failure, as are relay contacts, and whilst they can be functioning perfectly well, if Car is laid up even for a few weeks then a little corrosion can set in on a bad contact or bad solder joint and whammo, no start !!

Don't mess with it, buy a brand new one from MB and peace and harmony will return.

Do anything else, like trying to fix or buying from other than MB and all bets are off.

An MB K40 is often either cheaper or very close to internet prices, and the Original MB one has lasted 20 to 22 years in your case, depending which of the 2 R170's you have is the faulty one

HTH

 

[Dave2302]

There are 2 different K40's, so if part numbers don't match ....................

But I think you have proved the point