Here's the best advice I have for anyone who does it.
1)Remove first screw on plastic door sill on both sides. (the things on top of rug where door closes)Remove kick panels.
2)Remove panel under steering wheel.
3)Remove two nuts holding up steering wheel.
4)Remove screws where windshield meets dash board.
5)Remove 2 bolts left and right under dash but against sides of car (under kick panels).
5a) There is a square box in the center of the dash by the floor. Take it off and take those nuts off. And disconnect the wire harness and the get the panel loose and down out of the way.
6)Dashboard is now loose and can be pulled towards the seats.
7)On right side of dash hook a wire way up to screw that holds moulding clips, or pull the dash towards the seat and put a jackstand under the passenger side.
8)The whole heater box is now visible.
9) Remove necessary controls and electric plugs from heater box.
If you get a replacement heater core from Advanced Auto Parts, the new core has lines that swivel where they're attached to the actual core and you can actually fight in the new core without loosening the HVAC box.
If your replacement heater core has fixed (non swiveling) lines that feed throught the firewall, you will need to loosen the HVAC box to install the new core... Follow these steps
10) Now the secret: there are 2 screws holding it to fire wall on inside (one has a ground wire attached). The other is in the upper right hand corner facing up. The easiest way to get to the bolts holding the ground wire is to take out the glove compartment and then take out the airbag.
11) there are 4 nuts holding it from engine side of firewall(one is behind the electric panel on the passanger side). Remove all four of these.
12) Remove heater hose clamps with a hose clamp plier. This will take time, these clips are hard to get off.
13) Drain the AC freon.
14)the AC lines require a special tool that costs $9-12 at parts store. the kit has 6 plastic widgets. use the one that fits. play with an AC fitting near the radiator for practice first.
15) you should be able to pull the heater box out now.
16) Remember the dashboard is just pulled up high enough on the right to get at the heater box.
17) It is a good idea to change the A/C evaporator core while doing this job. They are both in the same box.
From my experience, it worked well to take a sawzall and cut the lines off of the old core then pull the cut lines through the firewall from the engine bay, which was easier then fighting those hoses loose back behind the twin setup.
On the inside, I just took a screw driver and bent the bracket closest to the firewall holding the core lines down since I couldn't remove the screw holding the bracket without loosening the HVAC box.
Another Tip: When it comes time to reattach the top of the dash, start with the middle screw.
Lavon
