Crawl under your dash and move the controls around and see if they are even hooked up.
They are only run by cable linkages and on some older Suzuki's the end of the cable is only attached to the peices that it is suppose to move by a little ring bent in the end of the cable that slids over a little peice of metal that it is suppose to move. If you find the end of the cable and it is not attached to anything. Find something to attachet it to in the immediate vicinity. It is probably it;s partner.
Hope this long winded confusing tip helps. Trust me if it is the same as mine was you will understand when you see it.
Hey, I just had mine apart.
Ok, under the dash on the passenger side, there is a black tube/air duct running from the fan to the heater core. You can easily pull it off. Get some light and look in the hole on the heater, now move the hot and cold lever. You should see one damper closing on the bottom of the heater core and the other on top opening and visa-versa.
It's a little hard to get your head in there, but it can be done. Easy, and at least you can see which isn't moving and trace the cables. They are easy to get at too.
'94 Chev 1/2ton 6"ProComp
(one day I'll do a SAS)
'89 Sidekick 3" body, 31'S
513's, E-Z Locker