Blower motor only works on high speed - 1996 Dodge Caravan

SOURCE: HEATER BLOWER MOTOR ONLY WORKS ON HIGH SPEED

THERE'S A SENSOR UNDER THE PASSENGER SIDE OF THE CAR UNDER THE GLOVE COMPARTMENT YOU HAVE TO LOOK WAY UNDER JUST LAY DOWN ON TOP OF THE MATT IN FRONT OF THE PASS SEAT IT HAS 2 SCREWS ON IT UNPLUG IT THEN UNSCREW IT TAKE IT TO THE DEALER IT COST ME ABOUT 30 TO 50 DOLLARS BUT THAT WAS THE PROBLEM I HAD. GOOD LUCK

SOURCE: my 1998 astro van blower motor only works on high speed.

No the motor is not bad or going bad, the heater blower motor resister is bad, thats regulates the blower speeds, its located under dash by heater motor 2 screws hold in heater box with a electrical plug to it.

SOURCE: 2001 ford ranger windshield wiper delay not working

its the fuse inside the fusebox under the hood. the box is right in front of the battery. I had the same problem. 4 dollar part. look it up in the owners manuel and your good to go.

SOURCE: My blower motor fan speed switch will work only on High.

I had a similar problem with my 03 Taurus. Does your floorboard on the passenger side get wet when it rains really hard? If so, Ford is aware of a defect above the fan motor which is behind the glovebox.
I contacted Ford directly and they had my local ford dealer fix it free and they gave me money towards a new blower motor which shorted out from the leak, it's possible it just your switch if there is no leak but you might need both the switch and blower motor replaced like I did. Hope this helps.

SOURCE: Blower motor on 96 Isuzu Rodeo does not blow on

if fuses are good, check for power at blower motor, when truck is running and a/c on. the resistor and the switch provide ground, so the blue/white wire should have power, and the blue/black wire should have NO power, if it does have power, then most likely the resistor is bad. if it has no power and the motor doesnt run, the motor is bad.

Testimonial: "I will give that a try.. and post the results.."