Question about Heating & Cooling
Hi Jim and Welcome to Fixya
First of all it sounds like all the Air dampers are intact as it WAS working fine and stopped. Here is most likely what happened.
The damper control cable that switches your air flow from recirculation to fresh air most likely has a bent cable or a loose cable retaining clamp that prevents cable movement when you move the selctor from recirc to fresh therefore not allowing the cable to travel full length.
What you can do is dive under the dash and watch the cable movement as a 2nd person moves the recirc to fresh air selector. When it is moved in one direction see of you can physically move the damper control drive arm further in the same direction after it has been moved with the selector. If you can still move the control arm then the control cable is not performing as it should and they will have to determine why.
Also the heater control cable that controls the position of the heater control water valve can cause similar problems for the same reasons above. Once again watch the travlel of the cable and try and move the arm on the water control vavle in the same direction. (Temp control selector movement Perfromed by a 2nd person) If it moves the cable and clamps will need attention.
Some vehicles have a 3rd cable that will mix hot air from the heater core with cold air from the AC evaporator coils. Depending on how the cabling is configured it usually is moved with the heat control. (Procedure same as above.)
It is never fun to dive under a dashboard........
If the AC Freon and Engine Coolant levels are fine you just have a cable issue that they need to correct. It should not be a major expense to get it fixed.
If they are a reputable shop the only thing you might be liable for is the cost of the new cable or clamps if required. They should wave the labor charges on a callback!
Thanks for using Fixya. Kelly
Posted on Feb 07, 2010
Well for best defrosting / demisting action the air should be set to fresh air, as moisture inside the cabin (due exhaling hot, humid air, wet floor mats, etc) can cause a high moisture content in the cabin and poor general clearing of windshield especially on an older vehicle where cooling capacity is going to be less then a newer one, due to wear/ system design, refrigerant used, etc. Also check that the condenser (in front of the radiator in engine compartment) is not blocked with debris which would cause insufficient cooling of hot refrigerant and therefore poor cooling inside the cabin. As well the blend door should be checked for closing off air from the heater core when the a/c and cool air is selected. Check for frost on the a/c lines that could indicate a restriction in the system like excessive moisture in the receiver / drier which could freeze as the refrigerant circulates and create a slow down in the flow of refrigerant and poor cooling. Also you could check to see that the a/c clutch is engaging on the a/c compressor visually by looking at it as the system is running (engine running) it should be cycling. Hope this will help you. But with a/c problems there are a number of things that can cause poor circulation that would require a/c test equipment to check it with. bring it to a repair shop that specializes in a/c service. cheers
Posted on Feb 05, 2010
Jim, if this is indeed an intermitten problem, then I am sorry to say that no one will be able to give you a good, clear, and concise way to track down the problem.
Being a 14 year automotive technician, and an automotive diagnostician, i am constantly faced with intermitten, and also hard problems to diagnose, and always always always the hard problems are the ones that get diagnosed easily.
The problem with intermittens are that there is so many variables that you cannot possibly see. So it takes a strong diagnostic backround, instinctual nature and basic electrical thinking to track these things down talents most mechanics dont have. You are going to be bombarded after I post this with people who say that they can solve your problem, but many if not all will be bad guesses at best.
Here are somethings to try:
Have shop connect gauges and observe, with ac system on low side should be between 30-45PSI high side 200-300psi, gauges should both be steady and non fluctuating. cycling of the compressor should not be evident.
If proper pressure is present and the system is not turning on, make sure the A/C button on the HVAC controls are on.
If button is on and still no compressor action then testing of the high and low pressure switches is needed, current should pass through both, sensors and end up back at the compressor to power the clutch.
Hope this helps and as always happy motoring
Posted on Feb 05, 2010
Have the guys check for a broken or rotten seal between the evaporater core housing and the firewall. If the foam has deteriorated the moister will get in and fog your windows up
Posted on Feb 05, 2010
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Tips for a great answer:
Jan 16, 2014 | Volkswagen Jetta Cars & Trucks
on May 07, 2010 | Ford Focus Cars & Trucks
on Apr 29, 2009 | 1993 Cadillac DeVille
Dec 15, 2013 | 2008 Chrysler 300
Dec 07, 2013 | 2007 Chrysler 300
Oct 04, 2013 | 2001 Audi A4
Oct 16, 2012 | 2004 Toyota Camry
Oct 28, 2010 | Mercedes-Benz SLK350 Cars & Trucks
Dec 10, 2009 | 2007 Volkswagen EOS Convertible
Aug 11, 2009 | Ford Expedition Cars & Trucks
32 people viewed this question
Usually answered in minutes!