I'm currently following the Haynes manual procedure for replacing the heater core on my 98 Blazer 4D 4WD. I've almost got the dash off but have two problems:
1 - I can't unplug the main harness plug located behind the glove box. It's a rectangular box with a small bolt in the middle that is shielded from the surrounding wires by a small piece of plastic. The manual says to unscrew this bolt before removing the plug; however, it will not unscrew all the way. Resistance will build and then suddenly go away - seems like something is wrong with the screw. Unless, of course, I'm missing something.
2 - The Haynes manual refers to a bolt underneath the dash just right of center next to a vent that is screwed into a "steel pencil brace behind the dashboard". The picture is grainy and I cannot find the bolt this is referring to, but I can tell not all the bolts/screws have been removed because the dash still does not want to pivot or move much.