Last post on Jun 03, 2013 at 8:17 PM
You are in the Chrysler PT Cruiser Maintenance & Repair
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Chrysler PT Cruiser, Heating / Cooling, Wagon
#121 of 235 Re: 2007 PT Cruiser AC blows hot, just stopped all of a sudden [dwjmd79]
Mar 15, 2011 (8:25 pm)
If you are sure that the low-speed radiator fan is coming on when you engage the A/C and cuts off when you disengage (assuming a cool engine), then the LPS is working. I am unsure of operation with high-pressure switch failure (which would be my next guess).
Double-check fan operation, and, if necessary, double-check the paper-clip test. The fact that you measured excessively high freon pressure indicates that the compressor must be running at some point. The pressures you describe can occur when the low-speed radiator fan does not operate, and this usually occurs when the LPS fails (yes, I know, vicious circle).
A good A/C mechanic can check all of this in short order. However, a crappy A/C mechanic will replace the entire radiator fan assembly before replacing the LPS when necessary.
#122 of 235 Re: 2007 PT Cruiser AC blows hot, just stopped all of a sudden [bthompson40207]
Mar 15, 2011 (9:48 pm)
I am sure that the radiator fan does come on when the A/C button is pressed. So the fan is operating correctly. I am not sure how to properly do the paperclip test. I am also not even sure if I attempted the paper clip test on the correct sensor. For the paper clip test I inserted a paper clip into the sensor attached to the silver soda can looking container close to the engine firewall that has the low pressure freon pipe attached to it.
I am also sure that the compressor does not come on at all at any point during my day or during driving or sitting idle. I did measure high pressure on the low end side when the car is completely cool. The pressure measurements were all taken when the ambient outside temp was 70 degrees F and the engine and car were cool, My friend thinks its a Low Pressure Switch or Low Pressure Sensor that engages when the low pressure side gets too high in order to shut off the compressor so it doesnt seize up or blow.
I did have the radiator fan replaced last year and I had the radiator fan relays replaced as well. The radiator fan defect is a known issue with the PT cruisers that causes the A/C compressor to disengage and blow warmer and the car to overheat. After the radiator fan was replaced last year the A/C worked great until a few days ago.
I will say that when the ambient temp was 75 or below and I ran the A/C at night it would blow so cold and the A/C coming from the vents would blow less hard yet extremely cold. When i turned the blower off and let the A/C "thaw" it would blow hard again and cold. It seemed to me like when the A/C was blowing cold at night it began to "freeze up" and the air coming out the vent would decrease in velocity the longer I let the A/C run. This happened at night when the outside temp was about 60-70 degrees. This was happening every so often for a few months. Do you think the "freeze-thaw" issue is the condensor or the blower that is causing the high pressure in my system and the compressor not to engage?
Is there anything else that migh cause higher pressure readings on the low pressure side?
And are there any other sensors that would cause the compressor to not engage?
I do appreciate any feedback or ideas. You have no idea how much it helps. Looking forward to hearing from anyone soon. Thanks
#123 of 235 Fan not activating Please help
Apr 29, 2011 (10:38 am)
I have a 2002 pt with the folowing ac problem. Low speed fan does not come on when ac switch is turned on. compressor cycles on and off. Works great while in motion. Have been reading this forum to help trouble shoot. I jumped the LPS connector with no change in compressor cycling. I put power to fan motor and got it to work. Changed low speed fan relay and that also changed nothing. fan still will not activate when compressor and switch are turned on. Is there a high and low side to the motor or is that taken care of by the 2 relays. What should i check next?
#124 of 235 Unusual A/C problem
Apr 30, 2011 (8:22 am)
Ok I have a 2001 PT. A few months ago I had someone change the radiator. I don't know if that has anything to do with my problem or not. Anyway, As things started to warm up I tried to use the A/C and it didn't work. I hooked the A/C gauge to the car and it is reading 60 to 70 psi which is into the red on this gauge. I started the car and the compressor isn't kicking on. I pulled the low pressure switch off and shorted it with a piece of copper. The car immediately started surging at idle. I disconnected the jump wire and hooked the switch back up and it is still surging. I'm at a loss. Any ideas?
#125 of 235 Re: A/C PROBLEMS ON 08 CRUISER [bthompson40207]
May 29, 2011 (7:30 pm)
I am having the same problem. A/C works great when I am driving and blows warmer air and jerks when I stop/idle. Can you explain how I can look at the the low speed fan with the flaslight to detect a problem. I would like to check it out myself before a dealership. Thanks:)
#126 of 235 Re: A/C PROBLEMS ON 08 CRUISER [opheliawest]
May 30, 2011 (7:01 am)
Well all I can say is I replaced the the LPS switch and it worked for a day but thats it. You can start there, my next step is replacing fan, but before I spend a 100 on that I'm taking it to a dealership to see if the run a diagnostic on it as I am having other issues as well. I'm noticing some oil on valve cover and not sure where its coming from. Someone said I may need to replace the PVC valve have either of you heard of this one?
#127 of 235 Re: A/C PROBLEMS ON 08 CRUISER [babydollspt]
May 30, 2011 (12:29 pm)
This is the first problem I have really had with my car. Hope you can get yours figured out. I hope it is the least expensive problem:)
I just called PEP BOYS and am going tomorrow morning to have a diagnostic test run and to have them look at the fan to see. I tried the self test, but could not find a good angle to see the fan properly.
#128 of 235 Re: What finally worked for my A/C! [bthompson40207]
Jun 05, 2011 (3:38 am)
Ok, this information is useful for me as I have an 08 that began having on and off AC issues at 49 k miles. Brought to dealer and they diagnosed a short and wanted me to shell out $950.00. The service separtment would not provide me with general information on the actual piece my car required but expected me to have the money to pay for it. Since last year (when the issues came about), my AC kicked on and off a total of 3 times. I have had no significant over heating issues with the car. It frightens me because the day before yesterday when I was driving the AC (after not working for 5 months) kicked on and blew dust in my face and scared me. I leave the nob on in the car because when I drive the cold air comes out of the vents and feels good in the AZ heat, but at a stay still nothing cames out only if there is a breeze outside. Do you think if replacing the parts you suggest will help my issue? It appears that there are similar issues with various years on this vehicle.
#129 of 235 Re: What finally worked for my A/C! [ginia740]
Jun 05, 2011 (12:04 pm)
Assuming that the freon is at full charge, perform the paperclip test first. Verify that the low speed fan is functional. You may only need the LPS or radiator fan/shroud assembly. These are two of the more common causes of failure. From the symptoms you describe, these are likely culprits.
Jun 06, 2011 (12:47 am)
What is LPS? Is that a switch? I am wondering because if I can purchase the parts and if easy to install perhaps my boyfriend can install. He, also hates the heat; especially in June. Thanks for responding.
Funny thing, today my AC did not work when I turned the car on. But, I started driving and began to turn on and off the nob for the AC and it turned on.