1997 JGC, A/C with ATC. Couple of issues, which may be related. First, have no heat on any setting. Coolant levels OK. Can feel warmth on the bottom of the Lower Housing. Diagnostic codes indicate the dreaded Blend Air Door. Second, water, not coolant, collecting on the front passenger floorboard. Maybe elsewhere, but haven't checked.
I have read the threads here on these types of issues. Dealer suggests that condensate drain has clogged and (1) shorted out the actuator and (2) is overflowing onto the floorboards. Fix is to remove whole unit ($1,000) and clean out drain. He happened to overlook the TSB recommended fix for drain cleaning by drilling hole in drain at floorboard. As it happens, that process has already been performed on this vehichle prior to my possession.
There are apparantly four doors that direct or affect airflow in the HVAC unit: (1) fresh air (2) Heat/Defrost (3) Temperature Blend and (4) Floor duct. #1 and #2 appear to hinge horizontally. #3 and #4 appear to hinge vertically. The parts diagrams I have found list three actuators: (1) Heat/Defrost, (2) Temperature Blend (3) Recirculating.
Question -
1. Which if any of these actuators are accessible without pulling the whole dash? And where are they located?
2. Can the actuators be tested in place to determine if they are functioning.
3. Which, if any, of the actuators can be shorted or damaged by condensate overflowing due to a clogged drain.
If you have read this far, thanks. And thanks further if you have any thoughts.