The most likely cause of excessive heat from the heater system is an improperly indexed temperature control cable. Other related causes include the following conditions:
• | A slipping self-adjusting clip at the temperature control cable end |
• | A loose control cable sheath retainer or bracket at the bottom of the heater assembly |
• | A binding or obstructed temperature air valve |
A hot air leak from the engine compartment to the blower inlet is also a remote possibility.