Access defrost mode valve? 1993

Take the dash radio/vent control cowling/cover off, look in there with a flashlight, down the throat of the vent duct. You'll probably see a balled up bunch of black cloth that prevents the proper opening/closing of the vent duct. I removed that black cloth by using a combination of a a bent coat hanger and a long pair of needle nose pliers. Had to rip it out in pieces. I then lubed up all the internal vent control linkages and it now works great. Oh, also had to use a bent up paper clip as a replacement spring retention clip as a small piece of plastic used as the spring retention broke off from that plastic post. The excess force I used when trying to work the stuck vent evidently broke the piece off and thus noticed the spring kept popping off the post. Try to get all that fabric cover off that you see while working it back and forth. Leave the foam on though, at least I did. Hope this helps.......