I have to change the fuse from AC/heater all the time,blower
motor works fine at all speeds,AC too...,fuse keep blowing,I
replaced it on daily basis,so,I disconnect the AC compressor,no
difference,as soon as the blower motor works for more then a
couple of minutes fuse gets bad,or,blower stops working and the
fuse is good,something needs to cool off for the blower to start
working again.Any ideas?,thanks.

Is the fuse in the fusebox? There was a retrofit to the 126 series that consisted of an external fuse holder that holds 2 fuses. The part (kit?) is available from FastLane.

It won't fix a blower motor with bad bearings or worn brushes.

Sixto
95 S420
87 300SDL