My 1999 Buick Century blower fan only works on HIGH. I beleive the issue is the heater blower motor resistor. Where is this located at on the 1999 Buick Century?
heater blower motor resistor on 1999 Buick Century
There is a fuse labeled "low blower". This fuse controls all speeds except high. Check that first. There is a separate fuse for high speed. If the fuse is good, the problem is probably the resistor module. It's right against the firewall behind the blower motor.
It is on the under left side of the blower motor, some of these cars have a blower motor module and some use a resistor.