1993 Chrysler T+C van 3.3L. The a/c and heater controls work correctly at floor setting and defrost setting, but will not work at the dash settings. Instead, if setting is changed to dash vent setting, air only blows out of floor setting. I realize this is probably due to an air-flow control door not working, but do not know if that is due to a bad dash control panel, or due to a bad diaphragm in a control door chamber (actulator correct word instead of chamber?) How do I check what is causing problem and how do I repair? I have figured out that the A/C-heater control panel is operated by vacuum lines to control the doors that direct the air flow to the different areas. So what I need to know, is if this caused by the climate control panel in the dash, or by a bad diaphragm, or by something else. If it is a bad diaphragm, how do I check to determine which one? (I have dash partially apart,and have found three). Then, if I need to replace a chamber, can I replace the diaphragm chamber while still in the vehicle, or do I have to pull the whole heater/ac assembly out of the dash (not good since this involves disconnecting freon lines, etc) and replace it on a workbench? So, first of all, is this problem being caused by a bad diaphragm in a chamber, or by a bad control panel, or something else? If a chamber, how do I determine which chamber, and once that is determined, what do I need to do to replace the bad chamber?. I have located one vacuum chamber behind glove compartment and two chambers below steering column. The six air vacuum lines from dash control panel are red, brown, and yellow to chambers under steering column, black vacuum out the firewall, and light green and dark green to passenger side chamber. The brown seems to have a vacuum when set at dash setting only, and the dark green line to pass. side chamber seems to have a vacuum at all settings.
It sounds like the Blend door inside your heater housing is stuck. If your blend door does not go to the desired position you will not get heat. There is an actuator that must me removed to make sure the internal door is not jammed. If ok you must make sure the actuator is moving, if not the actuator will probably need replacement.
BLEND-AIR DOOR ACTUATOR
REMOVAL
The air conditioning system can be equipped with either a standard single blend-air door actuator, or it can be equipped with dual actuators. The dual system has separate blend-air controls. This allows for separate control of the driver's side air, and the passenger side air
1. Remove the lower left side steering column cover. Refer to Instrument Panel.
2. Remove ABS control moduleNo airflow out of dash, but works at defrost and f - 80003e80.gif src="/uploads/images/80003e80.gif" alt="80003e80.gif" class="h_mi" />
3. Remove blend-air actuator connector.
4. No airflow out of dash, but works at defrost and f - 80003e98.gifn>Remove blend-air actuator
INSTALLATION
1. For installation, reverse the above procedures.
2. Perform the HVAC Control Calibration Diagnostic and Cooldown test. Repeating the test is necessary to clear the fault codes.
You can use a vacuum hand pump with a gauge to actuate the diaphragm these pumps are farely cheap sear usually has them you might be able to rent one from an autoparts store this will prove if it is your lie or your diaphragm also a haynes manual if you can obtain one should have a vacuum diagram and an explanation of operation hope this helps
Before removing or changing diaphragm where the vacuum line goes disconnect vacuum put a hose and apply vacuum you should hear the diaphragm move chec k them all if everything open go at the control at the control the vacuum are connected there disconnect those vacuum apply vacuumto those hose if you got one that not working block hose if its good change the control pierre
Check the vacuum hoses and make sure nothing is blocking the air to flow into the vents.
105 views
Usually answered in minutes!
THis answer was not sufficient-not even close. I would appreciate if someone would actually address my problem and answer my questions. Thank you.
I tried changing the control since it was an easy check and I found one at the junkyard-but did not correct. I will try to check vacuum and go from there. Right now it is too cold to work outside. Problem not solved, but at least you pointed me in direction to take. Thanks.
×