Hi,
So I had fuse 56 blown. Took out compressor, and it was dead. Replaced compressor with used working one, and replaced fuse. Car does not engage compressor. Switched relays with starter relay (same 5 pin with same drawings). Still nothing. Compressor is good- if I power it straight from the battery it works. Car somehow does not send 12V to compressor. Cleared all the messages with scan tool. Nothing. Any ideas? Thanks.

this popped up the other day - locked out due to fault....
no one came back with what u need to do to get it to run again.... take a read might get some clues - then you can tell us....

https://mbworld.org/forums/s-class-w...lfunction.html

Yes, it could be locked out, but how to revive it? I only have Icarsoft MBII.

indeed I too struggled with a good but limited Autel tool years back when mine went

I went to an indy I knew and almost straight away they had replaced the big fuse and had it working - the only thing between that and me playing was I had reattached the rear sensor and had driven gingerly to their place, I guess getting sensible readings - thus I suspect it needed sensible readings from the sensors and faults cleared to just run

Got it up somehow. Don't even know how. Tried so many things, and eventually it raised up.

sounds exactly how Merc would want it to work......