QuestionQUESTION: We have a 2001 Jeep Cherokee 4.0. We were having problems with the A/C, we would have it on, it will run great for about 40 mins, then it would stop blowing out cold air. We would turn it off for about 10 mins or so and turn it on and it will work again for the 40 mins and then we would turn off wait and it will work again. We took it to a mechanic, he said that we were low on freon and that it would need to be recharged. The recharging went great, freon was added, the mechanic said that he took it for a test drive (not sure how long of one) and it was blowing out about 44 degrees. We drove the car today, and you can tell it is blowing out much colder, but still having the same problem. The air will run cold for 40 mins or so, then blow out warm air, you shut it off, wait and turn it back on and it blow out cold, and then stops again after a bit and so on. Is there anything that we can check before we take it back to the mechanic? Any ideas would be great, thank you for your time and help. Cathy
ANSWER: After reading and rereading your question one one thought/question came to mind. Does the air just get warm or does the airflow out of the vents seem to slow down at the same time? My thinking is that the evaporator core is getting ice locked. This would tend to happen in areas where there is high humidity and the A/C controls set to Recirc. If this is the case, try setting the controls to vent or bi-level with the A/C on, use the Recirc button only for a short time on initial startup, and see if that corrects the problem.
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QUESTION: Thank you for the quick response, to answer you first thought, the a/c blows out cold air, and then it blows the same force but starts blowing out warm air, we turn off, for 10 min and then back on and cold air blows out. We live in Missouri, and it can get very humid. Will definitely set the A/C control to vent blowing outward and to the floor at the same time.
Thanks again, looking forward to driving it tomorrow and trying out the above to see what happens.
Cathy
ANSWER: Has the condition corrected itself yet?
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QUESTION: Russell,
Thank you for checking back, we drove it the next day and tried your suggestion and it still had the same problem, it would blow super cold air and then it would blow warm air. You shut it off and wait and turn it on and the cold air blows again. We have taken it back to the show where we had the ac recharge done to see if he can figure it out. He mentioned as you have that something is freezing up, and ran through a couple of things, and mentioned the high presser valve? So we are waiting to hear back on what the problem is. Would you like for me to keep you up dated on what he found?
Cathy
AnswerYes, keep me informed. You have an unusual problem and I'd be interested to know what fixed it. You mentioned a high pressure valve in the last followup, There is a high pressure switch in the system that protects the compressor that may be an issue. The hardest part is to catch the failure when it happens, otherwise all the pressure and sensor reading look normal. Thanks for the positive feedback.
