Repair Topics/ Air Conditioner-1 / Air Conditioner-2 / Air Conditioner-3

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Car Air Conditioner Questions and Answers

This category contains featured questions as examples and relate to most vehicles.

Answer: The problem you described is caused by a plugged condensate drain for the air conditioning duct. It should be no great mystery finding the drain under the car for anyone familiar with the mechanics of vehicles. Cleaning out the drain can be accomplished by either blowing air up inside the drain to dislodge what ever is plugging the drain or a small hooked wire can be used to hook the object and pull it out.

Question: 1999 Honda Civic EX 1.6 liter mileage 110,000. The air conditioning on my Civic stopped working intermittently this week, mostly upon acceleration, then stopped blowing cold air all together. I purchased a recharge kit (R134a) with a gauge, and upon connecting, realized the low side held approximately 100 PSI. I don't have an adapter to check the pressure of the high side. The low side pressure does not change with engine running or not. My thought is I might have a blockage. My question is, is there an Achilles heel of the R134a A/C system in this car, and do you have a suggestion as to where any blockage or stuck valve may be. I think I may have to resort to taking it in for professional service, since my ASE A/C certification ran out in 1992, two years before R134a became standard. Any advice would be helpful. Oh yeah, the compressor is turning properly.

Answer: Your problem could be that the vacuum lines have failed, blend doors in the heater-air-conditioning duct work are stuck or malfunctioning, fuses have blown, bad switches and or relays, etc. Additionally, we do not recommend non air-conditioning experts tapping into Freon lines as damage to the car or personal injury may occur.

Question: 1995 Chevy Astro Van. Bob and Ken, I have a 1995 Chevy Astro Van and the rear air conditioner is not working. The blower motor is good, I hooked it up to 12 volts and it works, when there is a load or the blower is hooked up the voltage drops down to 0 volts. The switch is good, the fuse is good and the rear condenser is getting cold, it's just not blowing out air. Is there a relay or something that is bad? All speeds for rear blower do not work, the front works great. Thanks Jim

Answer: Check the 12-volt circuit that supplies power to the blower motor with the blower motor on (with a load). There is probably a bad connection somewhere that fails under load.

Question: 1997 Isuzu/Rodeo 3.2L V6 mileage: 95,000. I am having a problem with my fan/blower. I can tell that the air is hot when using the heater and cold when using the AC, but the fan will not blow. I checked the fuse and also changed it and it still doesn't work.

Answer: Check for 12-volts at the blower motor. If 12 volts is present, replace the blower motor. If not, check for a faulty relay or fan switch.

Question: 1990 Ford Taurus LX 3.8 liter V6 mileage: 72,000. This car has an electronic automatic temperature control (EATC) system. The temperature and the blower controls work fine. But, no matter what flow direction control button I push i.e. floor, panel, automatic, or defroster, the air only comes out from the panel vents. This makes defrosting the windshield nearly impossible. Most dealers I talk to about it treat it as an exchange item, and a very costly one at that. Are these units repairable, and if so what is the most common problem for this circumstance?

Answer: The dealer is right; the control unit is not repairable. Check to see that the doors in the vents are not getting stuck.

Question: 2000 Dodge Dakota V6 mileage: 12,000. After driving with the a/c on, when I turn the vehicle off, there is dripping onto the exhaust that causes a pop and hissing noise. Any advice on what to do? The dealership doesn't seem interested in fixing it...

Answer: It sounds like normal condensation dripping on the exhaust pipe. What you might want to do is put an extension on the air-conditioner drain tube to get it away from the exhaust

Question: 1999 Nissan Maxima mileage: 134,000.  My Maxima climate control (ac/heater) fan is stuck on HIGH. It keeps running no matter if manually change the setting, change from AC to heat or even if I turn it off.   The only way I can turn it off is to unplug the blower/fan.  How can I fix this?   Thanks!

Answer: The blower motor is controlled by a speed control module that is probably shorted "on" causing the blower to run all the time.  Replacing it should fix your problem.

Question: 1999 Plymouth Voyager mileage: 86,976.   To Whom it may concern, my car air-condition has a foul smell.  What could cause the car air conditioner to smell?  Please list the possible causes.  Thank you.

Answer: The nature of an air-conditioner is that it generates condensation “water” as it cools the air passing through it.  The dust in the air sticks to the water and then when the car is shut off, the water and dust stagnates.  Consequentially, when the car is started the next day and the blower is turned on, you get a musty air smell.   The older the car, the more dirt build up and the stronger the smell. Try mixing 20% bleach and water in a spray bottle and spaying it into the intake of the heater system while on high speed fan this should kill the smell. Then let air out for 4 hours in dry warm place.

Question: 2002 Toyota Avalon cylinder Mileage: 68,000.  Our AC in our car has a small leak---a year ago we had the condenser replaced and added Freon and now is having the problem again.  One garage told us we need to have a kit installed to get away from Freon.  At the tune of $200.  The second garage says not to worry about the leak just keep adding Freon.  What are we to believe?

Answer: Older cars can be converted to the new style of refrigerate (R134-A). What we would suggest is to replace the system "o" rings these seal tend to dry up and cause leakage, the hard part is replacing the one at the evaporator, but is a must. Also check your air conditioning compressor for oily residue at the front of the compressor this is a sign that the compressor needs replacement.

Question: 1995 Chrysler New Yorker 3.5 mileage: 83,000.  Air Conditioner: My AC operates well while my mechanic is checking it out.  R-134 checked, and all pressures checked out, recycles normally.  Problem is when I get it on the road after a few miles it stops blowing cold air, Occasionally after driving farther it will start operating OK again.  My mechanic is baffled.  Can you give me some advice?

Answer: Yes, have your mechanic check the radiator cooling fan operation, plus check for proper refrigerant levels.

Question: 2001 Honda Civic mileage: 48,500.  When I'm driving down the highway WITH the AC on, the car feels like it jerks.  And when I take the car out of gear and put it into neutral (it's a manual transmission) the car stalls (and this happens WITH the AC on).  On the contrary, when I drive on the highway or put it into neutral WITHOUT the AC it runs smoothly and none of those things happen.  I tend to think it is the compressor.  Do you have any idea what it is?  Thanks a lot for your help.

Answer:  It sounds like your refrigerant level is low and the air conditioning compressor is cycling on and off. Have the refrigerant levels checked.

Question: 1998 Saturn SL2 mileage: 48,000.  After only a few months of owning this vehicle, it started leaking water in the foot well/floorboard on the passenger side of our car.  It leaked so much water that it soaked the entire carpet in the car and had water standing on the floorboard.  I took it to the dealer where I purchased it and the service department said that the A/C line had clogged up and needed to be cleaned out.  We have had this problem several times and had the carpet replaced twice (under warranty) and we have been told it will continue to happen as long as the line keeps plugging, is this normal?  None of my other cars have had this problem before.  Why this one?  We have also noticed in the winter that same area has a bad air leak and cold air is pouring in the floorboard on the passenger side, could those two problems be related?   I am taking my car in later next week to have the cold air leak addressed, but I wanted to get your take on the situation.

Answer:  You need to find out what is plugging the drain line to find the source of the problem. It must be some kind of marital that is dilapidating and is plugging the drain hole repeatedly.

Question: I recently had the water pump fall apart and pump coolant all over the ground, and the a/c compressor disintegrate making a loud noise.  Both were replaced.  The cooling system works fine, but the a/c worked only for a few weeks and now no longer cools.  The dealer will not look at the vehicle without charging me again (I had to take the truck back for a coolant leak AFTER they fixed it the first time).  Every repair is going to involve two attempts and multiple charges to me.  Two questions: Should I just dump the truck and buy something else, or should I try to get the a/c fixed.  Am I being foolish keeping this Chevy or is it time to trade.   Vehicle reliability and cost of operations are the two most important factors in vehicle ownership to me.  Thank you.

Answer:  A possible refrigerant leak could be the reason your air-conditioning is not working.  If you have the system checked for leaks, the location of the leak is likely in the area of previous repairs. Check for other dealers or independent repair shops to diagnose the problem properly.

Question: 1997 Dodge Intrepid mileage: 154,000. I have a hissing noise coming from the dash area and the air conditioning and heat are not working properly. The dealership put some dye into the a/c system and told me to bring the car back in a week. For $15.00 worth of dye, it cost me $88.50 for labor. In addition, they put two units of R134 refrigerant in the system for an additional $65.00. My question is this - does the dye need to stay in for a week and why put more refrigerant in the system if it’s leaking anyway?

Answer: There is a method to their madness. The air condition system must be charged with refrigerant and the dye to find the leak. Think of it a putting air in a flat tire to find a leak. They want to wait a week so the dye can escape and stain the problem area.

Question: 2001 Ford F150 mileage: 58,000. Air conditioning blows out defroster on hard acceleration I know this is probably a vacuum leak have been unable to find more than one reserve tank the one I found is not leaking.

Answer: Check for vacuum hoses that may be cracked or a loose connection. Another source of the leak may be the vacuum switch on the back of the heater/air condition control on the dash. Somewhere in the vacuum system is a check valve that may have failed. It is usually part of the vacuum reservoir tank.

Question: 1997 Ford F-150 mileage: 100,000. With A/C on, while driving it works fine, but when I come to a red light or any time I stop it stalls out the engine. I have to turn the A/C off and restart the engine. It seems as long as I have my foot on the gas pedal it works. What could be wrong?

Answer: From what you describe, the Idle Air Control (IAC) valve is sticking and needs to be replaced. The engine depends on this valve to control idle speed. If it is not functioning properly a stalling condition will occur.

Question: 2001 Ford Windstar mileage: 68,000. The air conditioner in my van makes a weird clicking sound and sounds like it's taking a lot of power from the engine. The sound starts and stops until I turn off the air conditioner or the heater. So is this normal or should I be worried.

Answer: The problem you describe is not normal. Your air conditioning system is low on refrigerant. Have the system checked for leaks and recharge.

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