Operation CHARM: Car repair manuals for everyone.

Test G

PINPOINT TEST G: INSUFFICIENT, ERRATIC OR NO HEAT


Test G1-G3:






Test G3-G4:






Normal Operation
Under normal operation, warm coolant flows from the engine through the heater core and back to the engine.

Possible Causes
- Plugged heater core.
- Coolant level.
- Temperature blend door.