Hello all! I am new to the wonderful world of MB, and my 1990 300E 3.0 has been doin' some mighty strange things! Car runs great most of the time but lately if the A/C is turned on the air pump engages and somtimes even the ABS pump as well. The engagement is intermittent (on/off/on/off sporadically) and will usually result in the engine dying. Also, the tach jumps up to about 2K while the "clutches" are engaged. Really wreaks havoc on the idle. Now heres the really wierd thing, if I disconnect the high pressure cutout switch while its in its "funk" problem goes away, reconnect it and..VIOLA! its back!

Can anyone of you nice and much more intelligent gents steer me in the right direction, or should I call the GHOSTBUSTERS!

Seriously Stumped