Last post on Feb 11, 2013 at 7:02 AM
You are in the Chrysler PT Cruiser Maintenance & Repair
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Chrysler PT Cruiser, Heating / Cooling, Wagon
#134 of 222 Re: What finally worked for my A/C! [ginia740]
Jun 06, 2011 (6:13 am)
The LPS is the Low Pressure Switch - a common cause of A/C failure. The LPS is what cycles the compressor on and off. It cost me $9.00 for a replacement at Auto Zone. Perform a search in this thread for my previous posts on how to troubleshoot and replace the LPS and the radiator fan/shroud assembly.
#135 of 222 Re: A/C PROBLEMS ON 08 CRUISER [opheliawest]
Jun 06, 2011 (4:35 pm)
I was having same problem. Last summer I took it to an a/c "expert" (his terminology) since I don't have guages etc.
He charged me $70 to tell me that I need an $1100 compressor as mine was "weak." I decided not to do it. This spring I took it to another a/c shop. He worked on it for about an hour with his guages and code readers. He said he would have to put it on the rack and pull the fan from the bottom to see if it was the problem as he could find nothing else wrong and that I would have to bring it back later for that. He didn't charge me and seemed embarassed that he couldn't diagnose it.
I took the upper radiator support off (6 bolts), leaned the radiator forward and took out the 4 fan shroud bolts, unplugged the wiring, and removed the fan from the top. I hooked a 12v battery to the ground and positive terminals of the wiring harness (3 wire plug). The fan would not run on low speed and was sluggish on high speed. I took the blade off the fan and oiled the fan motor bearings and put the blade back on. The fan worked from that point on both speeds. Apparently the motor is thermally protected and the dry bearing created enough heat to kick out the thermal switch causing the system to detect overheating and kick off the compressor at idle speed. I ordered a new fan that I will install as I feel that the problem will return due to wear in the fan motor bearing. The best price i found on the fan was partsgeek.com. $89 including shipping. Wish I would have taken this on from the beginning.
#136 of 222 Re: What finally worked for my A/C! [bthompson40207]
Jul 06, 2011 (1:21 pm)
So, after 5 years, I have finally found out what has caused my 05 PT to shudder and have idling problems. Mechanic thinks it may be the Radiator Fan Module. Is this the same as Radiator Fan Assembly??? Also, I read the post about the paperclip trick, however, I am a un-mechanical woman. I just have to take it to mechanics and dealerships. So, with that in mind, how would a mechanic tell if the LPS is the prob or if it is the Fan Assembly? Finally, is the LPS something that typically gets replaced when the Fan Assembly/Module is replaced?
Also, people keep posting on here that this A/C issue is a known issue with Chrysler. I called Chrysler yesterday and they knew nothing about it. They said they typed A/C into their database and nothing came up.
#137 of 222 Re: 2007 PT Cruiser AC blows hot, just stopped all of a sudden [dwjmd79]
Jul 06, 2011 (1:50 pm)
You had mentioned that this radiator fan issue is a known defect in PTs. I have a PT with this issue and I called Chrysler and they know nothing about it. They said if the part was "defective" that there would be a recall on it, but no recalls have been issued through NHTSA. Is this something that a mechanic told you or were you actually able to get someone at Chrysler to admit that there is really some defective parts on their precious PTs?
#138 of 222 Re: 2007 PT Cruiser AC blows hot, just stopped all of a sudden [hbtmmmom]
Jul 06, 2011 (3:52 pm)
Just look at the sheer number of posts here regarding the radiator fan assembly (and this is just one forum). It is not unusual to find them failing after only two years. There is a reason that these fan assemblies are in stock and so readily available at so many automotive parts web sites.
There is a big difference between a "Service Bulletin" and a "recall". A Service Bulletin for a defective part does not necessarily evolve into a recall unless these is a known safety issue. "No A/C" is not considered a safety issue.
#139 of 222 Re: What finally worked for my A/C! [hbtmmmom]
Jul 06, 2011 (4:08 pm)
A good mechanic will know how to perform the paperclip test. But, then on the other hand, many mechanics are not out to replace a $9.00 LPS. I and many others on this forum thread have been quoted anywhere from $600 to $1,200 for the"fan" repair. But, the LPS only affects the A/C and the defroster (the A/C compressor cycles in winter to remove moisture from the air stream blowing against the windshield). The only symptom you mentioned was the idle/shudder issue. Is your A/C also affected?
I'm surprised that Chrysler did not find anything in their "database" regarding A/C. Especially since it has been reported hundreds of times on the internet.
#140 of 222 Re: What finally worked for my A/C! [bthompson40207]
Jul 06, 2011 (5:19 pm)
Yes, the A/C is affected. That is how this finally got diagnosed for me. Thought it just needed refrigerant added, but the mechanic dug a little deeper when he discovered pressure issues and that the fan would shut off causing warm air to blow. Not sure if the defrost is also affected or not. I seem to remember a thud sound every time the defrost was turned on or off which is also something we hear when the A/C is turned on or off. And the car would shudder and almost die when stopped during A/C usage and I think defrost usage. I will have to check for sure on the defrost, though. Right now the focus is on A/C since it is hot. I will have to be in contact again with Chrysler. I think they are playing dumb. How can they not know of this? The dealership that will be servicing my car seemed to think this was a fairly common problem among PTs. He even fixed this issue on one last week. Turns out, that right after I bought my car, I took it into the dealership and told them about the shudder issue and that it felt like it was going to die when we were stopped and all, but they kept saying there was nothing wrong with it. It wouldn't shudder if the A/C was turned off during a stop light, though. Now we find out that the root of all this was most likely the fan issue. Infuriating since the car is no longer under warranty. But why should I have to pay for it now just because it wasn't diagnosed until now even though the problem existed 5 years ago when it was purchased?
#141 of 222 Re: What finally worked for my A/C! [hbtmmmom]
Jul 07, 2011 (8:21 am)
All of your symptoms can be due to inter-related issues. A properly functioning LPS is required for the the low-speed radiator fan to engage when the A/C is switched on; a properly cycling low-speed fan is required for the compressor to work properly; and, the compression is what trips the LPS. Excessive compression (due to a non-functioning low-speed radiator fan) can cause the engine to "shudder" because idle speed is insufficient to overcome the pressure in the A/C system.
As proven in these and other forum posts, problems with the LPS and the low-speed radiator fan (and ultimately the A/C) are common in the PT Cruiser. They are also not uncommon in other Chrysler vehicles.
Jul 08, 2011 (8:10 pm)
I had a pressure test done on my 2002 PT Cruiser AC and I was told that I had a leak at the top of the Condensor. Yet when I search on line I keep getting results for the compressor. Are these one and the same thing and just go by different names depending on the shop doing the work?
#143 of 222 Re: A/C repair [terry1703]
Jul 08, 2011 (9:19 pm)
No, the compressor and condenser are not the same thing. The compressor is the mechanical piston-driving device powered by a belt that compresses the freon gas. The high pressure vapor output of the compressor is fed into the condenser that is located adjacent to the radiator. The low speed radiator fan supplies constant air flow across the condensing coils which converts the freon vapor into a liquid form. An expansion valve after the condenser coil allows the liquid freon to form into a low pressure gas that flows into the evaporator coil inside the car. The A/C fan blows air across the evaporator coil and through the duct work into the passenger compartment. The low-pressure freon gas is sucked from the evaporator coil and into the compressor as the cycle repeats itself.
So, to put it in short form, your leak is in a coil of tubing in the exterior of the vehicle parallel with the radiator.