'89 300E no heat out of passenger side

Be sure that the thumbwheels are in the open position. Other then that, I'm told that there is a control unit that opens and closes the air blend doors. To replace the unit requires that the dash be disassembled. A difficult job.

Please let me know how you make out. I have a 95 420E with heater problems.

The vents are open. Air flows out of the defroster and outermost vent fine, and out of the drivers side frion and rear footwell vents, just no airflow in the front or rear passenger footwells.

Unfortunately, it is 21 degree's outside. With no garage, it will be at least a week before I can look at it, I like to work in at least 30 degree weather.