Sounds like the blower motor resistor is shot, you'll have to have it tested or replaced
November, 10, 2008 AT 10:02 PM
Where is the resistor and how can I test it?
November, 10, 2008 AT 10:46 PM
Its behind the instrument panel inside the blower motor housing, you'll need a test light and check each of the slots in the resistor(heres a pic) with the ignition key in the on position and the test light on a good ground, you'll test each slot as you are putting the switch on each speed.
November, 10, 2008 AT 10:49 PM
This is the instrument panel insulator that you will have to remove first