I guess it was about this time I figured out I was going to have to pull the dash in order to replace the wiring harness that had been hacked up for the narrowband O2 installation. Out came the steering wheel, combination switch, shift lever and radio (and all the various trim pieces around them) to make life easier. Note that I did not pull the e-brake, which I was to later regret. Actually removing the dash was pretty easy, the bolts are all relatively easy to get to. Once that was out I discovered that the heater core would also have to be removed as the wiring harness passes through the firewall behind it. Had to pull the radiator anyway for the intercooler installation, so drained the coolant. I also removed the HVAC fan, it was dirty inside and the sealing foam around the top was breaking down.
Swapped out the harnesses, just took my time and fed the old one back into the cabin a little bit at a time (moving between the engine bay and the interior), the new one went in the reverse of that. The hole in the firewall is slightly behind the A/C condenser so that is what slows things up. Cleaned up the fan unit using Q-tips (only thing I could find that would fit between the blades) and used some household insulation foam to reseal the top (IIRC it was 3/8", available in any hardware store's insulation section).
Swapped out the harnesses, just took my time and fed the old one back into the cabin a little bit at a time (moving between the engine bay and the interior), the new one went in the reverse of that. The hole in the firewall is slightly behind the A/C condenser so that is what slows things up. Cleaned up the fan unit using Q-tips (only thing I could find that would fit between the blades) and used some household insulation foam to reseal the top (IIRC it was 3/8", available in any hardware store's insulation section).