my dads 2000 something chevy geo.(corrola) stoped blowing low and medium for the blower motor only high. so does anyone know if this is a common problem. or what to look for. we think that the switch for the controll is bad. or that the relay of some sort is bad. any help guys. i hate forgin cars. dont plan on getting to involved with this. like buying a manual. but he wants to buy new relays that arent bad. so ....ideas experience.
Seeing as your Geo is built by/based on a Toyota, it may be having a problem my sister's old '89 Camry had. Her symptoms were the same as yours.
Turns out there is a resistor that actually limits the voltage (or some other electrical-type variable I do not understand) going to the blower motor, when you select one of the lower fan speeds. It was very easy to change.
Hers was located (if I remember correctly) somewhere behind/inside the center part of the dash - not too far away from the A/C controls. (Actually I cannot remember exactly were it was...this is a repair I performed many years ago, and she no longer has the car or the Haynes manual for me to look at.)
I do remember that the part was expensive from the dealer (typical) but I knew what I was looking for and found a good one at a junkyard.
You could actually see the broken parts on hers - it has 3 different sized wire coils, 2 of which that had broken. Kinda like a filamant in a light bulb that had burned out.
Hope this helps. Good luck.
Our cars have resistors just like these. Sounds like that's what's wrong, definitely.