Chrysler Repair: 96 Chrysler T & C LXI HVAC, control actuators, calibration test

Question
I followed your instructions re the ventilation control actuators and the result was acceptable with only the rear wiper LED flashing. However the cooldown test didn't work as the A/C and recirc lights did not flash. They just went out with the other LED lights after about 3 seconds before the calibration test started. Please advise. I'd really like to solve the heater problem since the temperature here is below freezing every day!

Answer
Hi Bob,
It is probably the case that the calibration test passed but because the ambient temp is so cold in the area that the a/c cooldown test couldn't be run as it requires that the system temp sensor not already be lower than the temp that it tries to achieve. So since the issue today is heat let us assume that the calibration of the distribution and blend doors test worked and we need to figure out why you aren't getting sufficient warming. You can deal with the ac in the summer!
The other factor in producing heat is that there needs to be sufficient flow of heated engine cooling water through the heater core in the box. The common way to assess that is to drive far enough to warm up the engine, then touch the surfaces of the two heater hoses where they pass through the firewall on the engine compartment side. If the flow through is good the temperature you perceive by touch should be about equally warm. If one side is hotter than the other that is an indication that the hot coolant is not getting through the coil as rapidly as it should. Were that your observation then I would suggest that you remove the hoses at their attachment points on the engine and put a garden hose on the colder side's hose and back flush the core with domestic water under pressure. If you can't make a watertight connection then go to an auto parts store and get a garden hose/heater hose adapter which is fairly common, but measure the size of the heater hose diameter in case they come in different sizes. After you flush it out see if you get better heat output.
The other possibility, but this would generally have caused a failure of the calibration test, is that the blend door electrical actuator is not working or the blend door is stuck in one position. The blend door is located on the driver end of the air box under the dash. You can observe its 'action' as you vary the temperature requested, but to see it you need to remove the underdash 'knee blocker' panel that otherwise prevents the view.
Roland