B: HEAT DOES NOT OPERATE

PINPOINT TEST B: HEAT DOES NOT OPERATE

B1 CHECK FOR VACUUM TO FUNCTION CONTROL

- Start engine and allow engine to idle.
- Disconnect A/C, heater vacuum source tube (black), check for vacuum.

- Is vacuum present?

- Yes
Go to B2.

- No
Service vacuum source tube (black) as required. Restore vehicle. Retest system.

B2 CHECK FLOOR PANEL DOOR OPERATION

- Turn A/C damper door switch to the floor position.
- Locate heater air damper door vacuum control motor.
- check for vacuum at blue tube and red tube.

- Is vacuum present at each vacuum tube?

- Yes
Replace vacuum control motor. Go to B3.

- No
Service suspect hose for cut or damage. Restore vehicle. Retest system.

B3 CHECK HEATER FOR PROPER TEMPERATURE

- Allow engine to run until operating temperature is achieved.
- Move A/C control to FLOOR position.
- Turn knob to full heat position.
- Turn heater blower motor switch.

- Is heater temperature OK?

- Yes
Go to B4.

- No
Go to Heater Core Test and service as outlined. Retest system.

B4 CHECK BLOWER MOTOR OPERATION

- Turn blower motor in all positions.

- Did blower motor operate properly?

- Yes
Restore vehicle. Retest system.

- No
Go to Pinpoint Test E.