I have a 1997 chevy blazer and the variable fan switch was broken, I replaced it and now the fan doesn't work at all some ppl told me. That its the ingition switch and some said its the regular (right off of the motor that changes it to variable speeds) is in need of replacing... Btw the head lights are dim and the running lights don't work what do you think?

SOURCE: Blower motor or resistor?

If it was the motor that went out then it would not blow at all. The resistor is the culprit that starts killing off speeds. It should be about $25 to $30 at an aftermarket store like autozone or advanced auto parts.

SOURCE: 1998 chevy blazer

check the fuse box under the hood and look for a burnt fuse (30A mini)
mine had the same problem and I check the fuses, found one that was blown,replaced fuse, now I have #4 position working

SOURCE: Blower motor or resistor?

Yes its the blower motor resistor.

More then likley theres some trash or something in it, or possibly the motor itself is on it's way out. There not that bad to pull out of that body car, just pull it out and see what you can see.

The blower motor is under the glove compartment

You can replace the resistor on your own. Please find a detailed diagram which would guide you to do it.

http://autorepair.about.com/library/images/bl629a-lib.htm

Thanks

SOURCE: Blower motor or resistor?

I had a truck about the same year with the same problem, it was the wiring harness, but id check the resistor and the fan first before replacing anythings,

SOURCE: need to replace rear brakes on 1997 chevy blazer

disk or drum?