I am a woman that doesn't know much about cars but can't afford to take mine to the shop. I have changed the blower motor but the heater fan will not blow. I was told to check the fuse and it looks ok. Your info said to confirm the resistor is at fault by first checking the operation of the switch, but i don't know how to do this. please help
how do i confirm the resistor is at fault by first checking the operation of the on 1993 Chevrolet S10
Goole image search, enter: 93 S 10 blower relay and look at the picture, IF the fuse is ok (IF) then that relay is most likely the problem. When the resistor fails, the blower should still work on high speed but high speed only! There is one more possible cause that i found some years back, on the drivers side there is a fairly large red wire, (12ga.) that feeds the relay which is on the passenger side. This wire's connection is under the brake booster at the firewall and can become loose and/or corroded! Good luck with it! Let us know how you make out.
blower resistors are cheap throw one in.