I never got an answer the first time (inspite of over 50 views) so I'll try again.

After having the a/c compressor replaced and changed over to 134a on my 1984 300SD I am experiencing the following symptoms:

1. Fan will not come on for heat unless defrost switch is pressed first. If you then push the middle button it will heat to preset temperature.

2. As soon as preset temperature is reached the fan shuts off completely. (I thought that it used to go to low). I can also hear a door slam shut underneath the dash. This happens with either heat or A/C.


I replaced the pushbutton unit with a rebuilt one last year after temperature problems ( The heat would come on full blast then the A/C, then the heat....etc).


PLease give me some help on this...I don't want to head to the dealer ($$$$$$) unless I have to.


Thanks!

__________________
Old age and treachery will allways overcome youth and skill!

1993 S500
1984 380SL

Have you checked the temperature control amplifier? Under the glove box, probably PN 000 822 10 03.