Chevrolet Repair: blower motor, s10 blazer, resistor pack

Question
I have a 2000 s10 blazer and the blower motor will only work on low speed.  What can cause this problem?

Answer
The resistor pack is usually something to think about when the fan operates improperly, although low speed requires most of the resistor pack to be working, so I doubt that is your problem.
So the fan switch would be my next thought, closely followed by the fan motor itself.
Use a jumper wire from the battery to the fan wire to see if it runs full speed that way.

Van