AC/HEAT BLOWER ON 99 BUICK CENTURY ONLY WORKS AT HIGH SPEED

SOURCE: A/C Heater blower fan does not cycle through all speeds

Yes it is the blower Motors Resistor board. It is up behind the blower motor, just under the glove box. You have to remove the black KICK panel with its two "Push Pins" that will break too. There are 3 screws holding that resistor board in, the back two are a bear to get to. Good luck.

SOURCE: heat/ac blower motor works on high. intermittent on other speeds.

Check the blower resistor pack - usually located in the heater air ducting in the blower fan airflow. Check for loose connections and open circuit resistors on the unit.
If speed 4 works always, its unlikely to be the blower motor ground connection.

SOURCE: Heat/AC Blower fan speed only works on High

hello, this sounds like a bad blower motor resistor!! its cheap and easy to change..if you need more info on locations let me know,, good luck.....marty

SOURCE: Heater/AC Fan does not work in our 1998 Buick Century

Fan will be under dash on passengers side , Removing glove box might be needed, Gm also uses a blower resister ro control fan speeds. First check your fuse and then check and make sure your getting 12 volts to the terminal at the blower, You could have a blown fuse, a bad switch, or a bad resister , if your getting voltage to blower motor then most likely it will be the motor. These are not to difficult to change. I hope this helps, please be aware I can only guess at what the problem is from my past experience.

SOURCE: Heat/AC Blower fan speed only works on High

Alot of people have the same problem with the fan switch and blown bulbs. There really is no fix for this. Jeep really screwed up when designing the heater control assembly. The cheapest solution is to buy another unit off Ebay. Can always go to the dealer but be ready to PAY for there mistakes.