Blowing Fuse on 1996 S420
 

On my 1996 S420 the number #20 fuse keeps blowing as soon as you turn the ignition on, very sudden everytime. I definitely have a bad electrical short. The fuse chart states that this fuse pulls the (control unit and A/C compressor and the automatic climate control). I have unplugged the A/C compressor and the fuse still popped. I took the push button unit out and the fuse still popped. I am assuming the automatic climate control is the push button unit, right? What exactly is the 'control unit'? Any help would be appreciated.

That fuse also powers-up the center vent assembly, the "smog" sensor, and the das control unit.

M.B. DOC could you tell me where the smog sensor and DAS control unit are that this fuse operates. Am I correct in my thinking that the automatic climate control is the push button unit? Thanks for the direction.