AC mode swing
 

Need help in troubleshooting ac problem on a 89 300e, 3.0 engine. ac blows ice cold, then once ac and ignition is turned off and car is restarted (after about ten minutes lapse/grocery stop etc.) it then blows warm air. This happens on a daily basis. Also cold air blows in frequent stop and go pattern. R12 charged with no leaks.

I would start by seeing if smoke is drawn into the little grill by the rear view mirror when the ignition is on. There is a small fan that runs any time ignition is on. It draws sample air through that grill and across the temp sensor.

Good luck,

Thanks LB for information. No smoke is drawn into the grille. where is the the temperature sensor located on the 1989 300e.
OK problem found, the grille and hole in the center of the grille was totally blocked by lint/dust/spider web looking tidbits, cleaned and tested ac, working perfect. Thanks again LB for steering me in the right direction.

If next time you need to find the fan, remove the glove box and it is forward and to the right.

Good job,

OK, its doing it again, blowing ice cold then on second restart, blowing warm air. Any other suggestion on fixing problem. Would the temperature sensor or (klima) ac relay
cause this.