General Overview - Start Here

Self-Diagnosis Flow Chart:

DESCRIPTION
To allow a technician to diagnose and repair the Auto Temp Control HVAC System efficiently.
There are five kinds of self-diagnostic systems and one auxiliary check. Each can be accessed by pushing certain switches on the Auto A/C Amplifier (Control Head). Available diagnostic systems are:
Step 1: Checks L.E.D.s and segments
Step 2: Checks each sensor circuit for an open or short
Step 3: Checks mode door position
Step 4: Checks operation of each actuator
Step 5: Checks temperature detected by sensors
Auxiliary Mechanism: Temperature setting trimmer

OPERATION
To enter self-diagnostics, do the following:
- Verify the fresh air vent lever is in the OFF position.
- Start engine and within ten seconds press the OFF switch on the HVAC control panel (Auto Amp) for at least 5 seconds.
- Proceeding from one step to another is done by using the temp UP and DOWN arrows
- Leave the engine running as you progress through the self-diagnostic flow chart.
- The final check is the auxiliary mechanism and you will press the FAN control switch to enter this check.