blower weirdness

my 2000 caravans heater swich seems to not stay still on low speeds all i hear is the vent opening and closing and then when i switch it to the higher speeds it stays its a pain in the butt cause of the noise

my 2000 caravans heater swich seems to not stay still on low speeds all i hear is the vent opening and closing and then when i switch it to the higher speeds it stays its a pain in the butt cause of the noise



I have a question. Does your air (A/C or heater) switch from the vents to the floor when the motor is in a strain? My 1994 Caravan does this and a mechanic told me it's in the A/C & heater controls. If you have another problem, it may be a bad blower motor.

my 2000 caravans heater swich seems to not stay still on low speeds all i hear is the vent opening and closing and then when i switch it to the higher speeds it stays its a pain in the butt cause of the noise
sounds like the blower motor resistor is bad ,probably needs to be replaced.Seems to be a fairly common problem.

If air routing (venting to floor/dash/windshield) changes when the engine is under heavy load, that suggests to me that the "doors" in the air routing control "box" are powered by vacuum. If a vacuum line leaks, there is not enough vacuum to power the "diversion doors", so they slip into default position, which on most cars is to the floor. When engine is running at average load it provides lots of vacuum so heater vents work fine. Under heavy load the engine provides much less vacuum, & a leak makes it worse. Look for a vacuum leak - vacuum hose is cheap.


my 2000 caravans heater swich seems to not stay still on low speeds all i hear is the vent opening and closing and then when i switch it to the higher speeds it stays its a pain in the butt cause of the noise