My heater fan, blower on toy corrola -88 will only go on full speed or next to full speed. What is the problem? Is it the fan or the switch?
/Petrol

sounds like the fan is slowly going...how long has it been doing this? or has it always been doing it? either way If you want I can sell you a fan and the switch for $35.00 outta the 88 Corolla I have for parts.

The problem is on the Heater Resistor which is located next to the blower motor. It is a little black square with a conector attached to it. it is held in by a phillips head screw. Take it out and see if any of the elements in the resistor are broken. The resistor steps down the flow of electricity for different switch setings. The blower runs on high when there is no resistance in the circuit. Chances are the last two resistors are broken. Bone yard- about five bucks.