The dryer is a pretty straightforward 1996 Maytag. It had started making very bad noises recently, so today I took it apart to find the source. Turns out noises are coming from two sources - one of the drum rollers, and the fan impeller. The worst noise comes from the impeller, and I can't figure out what's wrong with it - I'm surprised that the plastic impeller can spin freely on the shaft (without the shaft moving), but I can't find any evidence that anything is broken - is the impeller supposed to have a part that engages with the flats on the shaft and forces it to turn at the same speed?

It may be a moot point, because I managed to introduce a new problem. I wanted to see the impeller spin, so I plugged the dryer in (with the control dial set to an "off" position) and was surprised to hear the buzzer come on for a few seconds, followed by an electrical short. No idea why it would have tried to energize anything, but that's beside the point now. The part where the electrical damage appears to have occurred is on the thermal fuse (one of the terminals was blackened and damaged), but the fuse is still intact. Unfortunately, the dryer is now totally dead. I searched around and found no other places where electrical connections are compromised. Any good place to start troubleshooting this?

Thanks for your reply. The model number is LD7314 or LD8304 or LD8414 (I'm looking at the manual written for those three models). The shaft has flats; the impeller is held on by a lock-ring, but is not threaded. The plastic ring of the impeller that fits around the shaft is divided into four segments, so that it could be compressed down around the shaft - I guess I could try a hose clamp, although that would introduce an imbalance.

Yes, I did check for continuity across the thermal fuse, and it appears to be fine (then I shorted the leads around the thermal fuse just to be sure, and still had no sign of life from the dryer).

Doh! :o
I had neglected to check the house breaker switch - your suggestions helped me get that far...
So now the unit is working sort of - except that it turns on when I push the start button, regardless of the setting on the timer dial. The dial does correctly distinguish between modes with and without heat, and makes its faint clicking sound when not set to an "off" position - but somehow its ability to disengage the dryer function is gone. I have to break the door switch to turn it off. Looking at the site referenced in the previous post, the timer is a pricey part - if that needs replacing I'm probably looking at purchasing a new dryer, given the age of this one. Is there any hope of resolving the problem without purchasing that part? I checked the terminal connections on the timer, and they all look OK.

Thanks a million - your advice has been right on. :) I managed to free the contact, and the dryer is now back to its old condition - with a new blower wheel assembly on order.
Rob