Heater Fan DEAD + speed switch loose

Sort of urgent as we have a snow storm. The interior fan for my
heat (and AC) suddenly stopped working in my 1995 Chevy Blazer.

Previously, the interior blower fan would spontaneously change
speeds for no apparent reason, but I always thought that was
some sort of control regulation. Was like that for years.

What's interesting is that when the fan abruptly quit, totally,
the circular speed-control switch (vertical, that twists)
suddenly feels LOOSE, where before it would click through
different notch like positions from low to high.

Anyone know where I can get a replacement speed-control
switch and try putting that in. Any suggestions on what else
it might be?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7950428452&category=33545

Also, check you fan first.

I replaced the fan switch in mine in just a few minutes. Once the control assembly is removed, it's held on with two screws. OEM list is $15.49

Thanks for taking the time to answer.

First, the part on Ebay is exactly what I need, but someone is bidding on it.
There has to be some way for BOTH Chevy Blazer owners to get that part
and fix both Blazers, instead of one of us losing out on a $19.95 part
(starting bid). Sure, I can go to my Chevy dealer who will want a
small fortune for it, but it's a start.

Second, I tried to find the fan and couldn't. There is some assembly
above the passenger's foot space that looks like it might house the
fan, although it's an odd place for it (inside the cabin).

Inside the glove box, I found a panel that says "RELAY ACCESS"
and with some significant difficulty got that cover off without
breaking it. I saw two very small black plastic boxes which I
gather are relays, but what they are or what they do or why
I care or what do with them, I do not know. I was hoping I could
see the blower fan from the glove box, but no luck, I can't see
anything else but a bunch of wires.

Inside the engine compartment, just in front of the glove box on
the other side of the firewall and right in front of the passenger,
there is a very big plastic cover or shroud that covers some equipment.
Tubes from the A/C compressor go into that shroud, so I think it is related.

All the way on the passenger side of the vehicle, there is a very small
connector plug that plugs into the big plastic cover. This is the only
thing I could find that has a purple wire. On other boards and posts,
people talked about the purple wire being loose as a common reason for
the blower fan to stop working. Well, I found a purple wire. But it does
not look like anything that could have a bad connection the way people
describe it. Also, some talked about an in-line fuse, and that doesn't
look right. I suppose I could jiggle and clean it, but I'm still not sure
I'm in the right place.

This plastic shroud says something about "cut here" but I am not ready
to start ripping it apart to access the blower fan, at least not without
knowing that's where the blower is. I cannot find any way to remove
the plastic cover.

Also, I got the AC/Heater Control removed (hanging from its wires)
and I tried shunting across the connector tabs of the speed
control. I thought that if it was broken, I could "short" around
and bypass the speed control switch and get the fan to run.
However, when I shunted across the wire connection tabs,
nothing happened. But I also ran a 12v light bulb across the
connection, and the bulb did not light. I would have thought that
if the heater control were working properly, and the problem was in
the blower fan, there would at least be voltage across the speed
control switch, and I would see the light bulb light up. So there
does not seem to be any voltage running to the speed control
switch.

Well, if there is someone bidding on it, YOU CAN TOO!

Just wait till the last minute and out bid him.

Take the fan out and see if it will run directly off of a 12volt source.

Do you know where the blower fan is for the heat?
Is it inside the cabin or in the engine comparment? I see
something above the passenger's feet that might be it,
but I don't know how to take it apart.

Back of the Engine bay

Passenger side