No control valves are used. Engine coolant is circulated through the heater hoses to the heater core at all times. The temperature is controlled buy a blend door actuator under the dash. Here is what they look like. Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.
Image (Click to make bigger)
SPONSORED LINKS
Sunday, September 11th, 2011 AT 9:56 PM