Blower motor woes

I bought a 98 Express with 132K on it. The blower motor ran on speed 1 (low) 2, and 4 (high), but did nothing on speed 3. At 159K it died, I gave it a tune-up, (it's first! Ever see a spark plug with 159K on it??) and changed the leaky waterpump and fuel pump, which was the reason it got towed home.

So basically I went in to EVERYTHING. Disclaimer: I know nothing and am your basic automotive hack.

Everything works - EXCEPT now the blower motor ONLY works on speed 4, high. In my (limited) experience, that's a good way to kill a blower motor, but this just can't be a blower motor problem. What'd I do wrong?? I also went into the relay box before buying the $ fuel pump - ouch. So is there a relay or fuse I should look for?

Also, when changing the thermostat, there was a ground wire on one of the posts holding the thermostat in place - which I broke taking off. I got it back on, between the toothed washer and the nut and cranked it down to hold it in place - or so I'm hoping. Could that really be my problem?

Which blower motor are you having a problem? It sounds like the switch if it is the air or heater. On the tune up, did you change the rotor and cap and wires. Quite a job to get the plugs out so you may as well go all the way with everything open.
Fred

Yeah, quite a job all right! The waterpump is even harder to get to than the plugs ... replaced everything recommended but seeing all those sensors and thingies sure made me want to replace more.

Sorry, didn't realize there was more than one blower motor, but I'm talking about the one controlling the heat and A/C. The switch would be a good idea to try - is it on the fan speed controller?

If the blower works at all the problem is most likely in the blower control module. On my '04 the module is on the plenum just to the left of the blower as you look at it with the hood up. Your '98 may be different.
FWIW
YMMV

Thanks for the replies. One says the switch, and the other the control module. Are you both referring to the same thing? Finally got my Hayne's yesterday, and it refers to a 'resistor,' with a relay in it under the hood but it doesn't say where, and the 'control panel' which is on the dash i.e., how you operate it. Clearly that's easier to get to, but is there anything there that'd fix this?

The module and the switch are not the same part. The module is often referred to as the resistor. Look for the module/resistor on the blower plenum under the hood. There will be wires running from it to the blower motor.