If the blower doesn't run at all, then check the blower fuse since it may not be the resistor assembly. Another test is to see if you have 12 volts at the blower motor when the fan knob is set to "High". If you use a test light, the light should be full bright, and get dimmer and dimmer as you select lower fan speeds. If that's the case, then the blower is likely broken. A final test is to apply 12 volts to the blower itself and see if it spins. If it does and the trouble light didn't glow in the previous test(s), then problem is in the wiring and/or resistor assembly.
Good luck, and let me know how it turns out.
The resistors look like coils of wire. When installing them it's important not to bend the coils so much that they touch and short out. If they should touch each other, they will short out and the fan will run at the wrong speeds (if at all).
The resistor assembly is located in the fan housing because they get hot in operation (somewhat like a toaster element, but not *that* hot). The air from the blower keeps them cool. If a resistor burns out, then you lose the speed(s) associated with that resistor. If you lose all but the highest speed, then the entire resistor assembly has blown (it has a thermal fuse that opens if it gets too hot, rendering the whole assembly moot).
Sorry for the delayed response - I've been away for a bit.
Yes, you can squeeze the resistor assembly out when the glove-box is removed, though you have to be careful not the bend the resistor coils when installing the new assembly. Removing the old one will be good practice for putting the new one in. Note the orientation of the old one - the new one has to go in the same way. The new one can be installed in one of two directions, but only one fits correctly and allows the wiring harness to plug in.
The resistor is not the same as the ECM. The resistor assembly simply steps down the voltage to the blower motor to provide the four different fan speeds. A full twelve volts running to the blower (i.e. - no resistance) gives you the highest blower speeds. The fan-speed knob selects the various resistors to give you slower speeds (1 resistor is med-hi, two resistors is med-lo, and three resistors is low).
Hi Kirk - I read a post of your reply about Replacing a Front blower motor on a 95 Suburban.
My question is: My blower is good. I want to replace the Motor resistor. Will that require simply roming the glove compartment? And is the resistor the same as an ECM? I have a new resistor purchased for $17.00. Fan went out gradually2 months ago - as other members have experienced here on GMTC... Please help. Arno