Make sure the coolant is full. Check to make sure the engine is running at a normal operating temp. If the all checks good, start the engine, let it warm up with the heater on high, and feel both heater core hoses. Both should be hot. If they are, check and repair blend air door. If only one gets hot, try flushing the heater core.
Monday, April 4th, 2011 AT 6:26 PM