Blower Motor Draws In 100 % Fresh Air Only at Full Capacity

COMPLAINT:
Blower motor draws in 100 % fresh air only at full cooling capacity.






Cause/Remedy:
a) Interruption of electric line from relay air-conditioning system terminal 87 or from low-pressure switch (27) to electronic switching unit for temperature control terminal 2.
Eliminate interruption.
b) System not adequately filled with refrigerant (R-12 may be leaking) or pressure switch (27) defective.
Check air-conditioning system for leaks and refill or renew pressure switch (27).






c) Switchover valve (17) damaged or vacuum connections mixed up.
Check switchover valve and replace, if required.
Check electric activation of electromagnetic switch-over valve and fix.
Check vacuum connections according to vacuum diagram and correct.






d) Electric switching unit (9) for temperature control defective.
Renew electronic switching unit.
e) Control unit shorted. Renew control unit.