A/C - Compressor Belt Protection System Description

REFERENCE ELECTRICAL
NUMBER 013
DATE 05-16-86
MODEL AE (FR), ST, SV
CV, CE


CONDITION:

The indicator lamp in the A/C switch begins flashing with the air conditioning switched on in Camry, Celica, Corolla SR5/GT-S, or Diesel Corolla models.

CAUSE:

A possible cause is that the air conditioner amplifier has sensed a compressor malfunction and/or drive belt slippage, and has disengaged the compressor magnetic clutch to prevent reduction of alternator or power steering pump output, and/or belt damage.

CORRECTION:

Determine the cause of the compressor malfunction or belt slippage and correct as necessary.

NORMAL SYSTEM OPERATION:

NORMAL SYSTEM OPERATION:

The air conditioner compressor is equipped with a revolution sensor. The output of this sensor is compared by the A/C amplifier with engine RPM. If the amplifier senses a drop in compressor RPM relative to engine RPM it determines that a problem in the compressor has occurred. If this condition continues for longer than 0.6 seconds, the compressor clutch is switched off, idle up is released, and the A/C switch indicator lamp flashes. The indicator lamp will continue to flash until the ignition switch is turned off to cancel the flashing light.

See also TSB Volume VII, Electrical Number 020