Heater won't blow hot air. Blows only cold air. Servomotor and water valve working properly. Hoses are not warm to touch. Disconnected hoses from engine, coolant easliy flows thru both heater cores, this vehicle as front and back a/c and heating, no hot air from both units, hoses and connections have no obstruction. While hoses disconnected from engine ran engine, no fluid exited engine. I'm thinking maybe thermostat not working properly to flow hot coolant thru both systems.
Mar 28, 2010 at 12:07 PM