99 grand caravan air/fan only works on high

[jmbcastle]

Our air/fan only works on the high postition and then you can tell its at a diminshed rate. There is also a humming noise from the air/fan too when it is in this postion. Does anyone have any ideas of what is going on. The fuses are all checked and are fine.

[hundahunta]

you probably need to replace the resistor block. the possible you have rubbish in the HVAC housing or you have a bad fan motor..

[yogi_123rd]

I am not too familar with the setup on the caravan, but I did have a simular problem on a GM model. Most of the car companies use the same design.

Your fan should have two circuits: High speed and (possibly) multiple low speeds. The low speeds are typically implemented by putting a resistor block in the circuit which cuts down the voltage and current to the blower motor. This resistor block would be located in the blower motor housing accessable from the engine compartment. The unit is just a bunch of wire coils. When it goes bad, the wires usually corrode and then burn thru. All or some of your low speeds would be lost. The wiring of this resistor unit then goes to a relay which sends reduced power to the blower.
High speed is a seperate circuit usually hot wired thru a fusable link wire instead of a fuse.

You need to check the blower motor resistor for burned thru wires. If they look ok, it is the relay that has failed. Follow the wiring from the blower resistor to the relay that it will connect to. Replace that relay.

[Rayy]

I've been there, I had to replace the blower motor in my 98 Grand Caravan. It wasn't hard. Get yourself a repair manual and have fun. The blower motor is behind the glove compartment.

[vipergg]

Have the blower resistor replaced . Just had mine replaced because I was missing one speed on the motor .