System Check - HVAC System - Manual

Electronic Air Conditioning System Check - Normal Result:

SYSTEM CHECK - NORMAL OPERATION

NOTICE: If the results are NOT as illustrated in the Check refer to the Symptom Table for diagnosis guidance. Testing and Inspection

TROUBLE SHOOTING HINTS:
^ Perform before consulting System Check (see image).

BLOWER PROBLEMS:
^ Check LH underhood fuse block, fuse 3.
^ Check Instrument Panel (I/P) fuse block, fuse 17.
^ Check that grounds G103 and G2OO are clean and tight.
^ If blower runs all the time with ignition switch at "OFF," check related wiring for a short to battery. If wiring OK, replace high speed blower relay.


COMPRESSOR PROBLEMS:
^ Check relay center, fuse 5.
^ Check I/P fuse block, fuse 11.
^ Check that A/C compressor clutch connector is firmly seated.


AIR DELIVERY PROBLEMS:
^ Check I/P fuse block, fuse 17.
^ Check for manifold vacuum to vacuum tank at black hose.
- If vacuum is not present, check hoses back to engine intake manifold tap. Assure vacuum check valve is operating properly.
- If vacuum is present at vacuum tank, check for vacuum at violet hose.
- Check black hose to cruise control servo. If hose is OK, replace vacuum tank.

^ Check operation of A/C temperature valve by setting temperature lever to "COOL," then to "WARM," then back again. A/C temperature valve should move evenly through full travel each time temperature setting is changed. If valve moves unevenly or erratically, make sure valve Is not binding.