Initial Inspection and Diagnostic Overview

Try the following checks before doing the System Check.

1. Check Fuse 19 and Fuse 20 by visual inspection.

2. Check that connectors are firmly seated on the Heater Regulator, Water Shut-Off Valve, Interior Temperature Sensor, and Compressor Clutch.

3 If Rear Blower Motor only operates with Rear A/C Control in MAX, check GN/YL, BU/BK, and GN/VI wires. If all wires are OK, replace Rear A/C Control or Transistor.

4. If any A/C Panel Light or LED does not light with Park Lights on, check GY/RD, BR/WT, and bulb for an open (see schematic). Repair/ replace as necessary.

5. If either the Heater Blower or A/C Blower does not operate at slow speeds but both blowers operate at maximum speed, replace the Final Stage for the affected blower.





This procedure is an overall check of the Heating and Air Conditioning System. Each of the steps can be performed without the use of tools and without disassembly.

Even though one or more steps may not give the correct result, complete all of the steps to reveal all the symptoms that may exist. Refer to System Diagnosis when a result is not normal.

Complete this procedure with the temperature outside the car above 60 °F (16 °C) and the engine running at idle.