Why does 2000 Eddie Bauer explorer heater only works on high?
The blend door is on a vertical axis in the Explorer and it sounds like when you set the fan to high, you are blowing the door to a position where the heater core is open. The root cause of the problem is a broken blend door. Once the door breaks, it “blows in the breeze” and there are different combinations of turning corners hard, hitting bumps, changing fan speed, switching mode, etc. that will get temporary heat. The blend door has to be replaced to regain control of the system. This is a common failure on the Explorer and is an expensive fix at the dealer. Follow my user name to my Bio Page for a pointer to the HeaterTreater web site. This site has diagnostic information on this particular problem and an inexpensive fix.
