The first and second settings do not work on the fan for the heater/ac?

SOURCE: Fan motor works on high

Really common problem on Fords. My '00 vic had it and my friends 06 mustang had it. The problem is the blower motor gets old and starts drawing too much amperage. The motor is controlled by (on manual HVAC systems) by a nichrome resistor bank located near the heater core. The extra amperage blows the thermo-resistor in the bank, and also does some damage to the corresponding harness. The reason it work's on "HIGH" is because that setting bypasses the bank completely. You can fix the problem pretty easily yourself but it is sort of annoying. First go get a new blower motor, either from Ford or some other place like Napa or autozone. Probably one of the latter because sometimes it seems dealer's aren't always the most cost effective solutions =] Now head on down to Ford and pick up the resistor bank (and most likely the harness, but check if it's burnt first) park your car, let it cool down, and pull off the radiator cap, keeping it on the hole (this keeps the pressure equal, and just set it on the hole so no random stuff gets in) pull off the coolant lines to the heator core, unbolt the resistor bank, set it next to the next new one, and wire up the new harness one wire at a time. plug in the new one, bolt it in, and reinstall the coolant lines. then put in the new blower motor, it should be on the lower passanger side on the engine bay. Now go enjoy your new fan speeds!

SOURCE: Heater blows cold, and fan switch only works on 4 and 5

working on 4 and 5 speed that the resistor that broken cold air you got to move the selector to see the motor that move the trap hot and cold sometime when the motor was not move to the hot side for a long time its jam the motor on the passager side under dash put to hot and gently tap the motor tanks pierre

SOURCE: Front AC/Heater Fan Out, 2001 Dodge Durango

it could be that fan rester went out. pick up a repair manual from Napa. look to see if you need to take the dashbord out. some of this are lockated betewn the fire wall and the blower moter housing. i have had a hard time looking for on on the internet.

SOURCE: 97 Nissan Altima AC/heater fan only works on highest setting

Sounds like the blower resistor module needs to be replaced. Could also be the switch.