Fan Speed not working in speed 1-3

My '98 chevy malibou has 5 fan speeds for the interior AC/vent. Only speeds 4-5 work, and 1-3 seem to not work or be idle. Is there something I can do to diagnose and repair this problem? I don't want to have to blast my AC anytime I want to use it, uses too much gas!

 

There should be a resistor in the system that will control that, but I'm afraid I don't know where exactly it would be located on your particular car. The one in my wrecker is actually mounted in the heater core/ac evaporator box; Has a plug with, I think 6 terminals (3 speed fan). You may be able to start at the fan and trace wiring until you run into it, but access may be very tight with glovebox, pax side air bag, etc in the area. Also, the switch itself could be bad; that will require a multimeter and electical troubleshooting knowledge.

Late note: Found this elsewhere here on diy.com:

Q. My friend has a 1998 Chevy Malibu and her HVAC controls speeds "1" and "2" don't work. I know that this is a common problem with 1997-2002 Chevy Malibus, but don't know what the problem is, what the solution is, and how much it would cost to fix the problem?

A. Aside from the MVAC controls, you should find the same problem in heater mode. Your resister stack is bad. The blower motor resistor is located on the passenger side, under the dash. You need to remove the closeout panel, under the glove box. Look up in there and you will see the blower motor, and just over and off to the left you will see the blower motor resistor. Two or three screws secure the heater box - they are 5.5mm (7/32).

 

Anyone know what to do or how much it might cost?

 

I just purchased a 2001 with the same issues. I have bought the resister module but not tried it yet. It was about $32 at the chevy dealer. Good Luck.

 

Where can I get step-by-step instruction for replacing the control knob or the resistor module?

 

Like John (tow_guy) said, location of this module varies, so a step-by-step would be difficult.

I tend to recommend subscribing to alldatadiy.com

It costs about $25 for the first vehicle, but the repair procedures are great and is specifically for your car.

Being subscribed too this has saved me thousands of dollars in labor costs because I could do all the work myself.

I do not like the Haynes/Chiltons guides because they are not specific on items like this. They also cover too many model years in one book which makes it difficult because things change within cars from year to year.

 

Used to be two 1/4 inch screws and a plug on the side of the heater box.
And by the way it does not matter what speed your A/C runs it uses the same amount of gas.