interior cabin fan does not work on first 2 settings

[mikekaminski]

interior cabin fan does not work on first 2 settings is there a fuse i can check or is it part of a bigger problem?

 

[MustangLX-5.0]

First two? There are 4 speeds. The very back position is Low speed, not off. It's not a fuse issue. The problem is the blower motor resistor circuit. The thermistor (which is temp sensitive) on the resistor board is bad, or the leads on the thermistor are highly corroded. You can find the resistor circuit attached to the blower motor. Look right under the dash right under and behind the glovebox. You'll see a wire harness with about 4 wires attached. Where it plugs in, you'll see 2 screws. Unplug the harness and remove both screws. It should fall right out. New part is about $15 or so.