OK, I'm thinking it may be a condenser fan problem. When the engine is cold and the A/C is turned on it is my understanding from some research I've done that the fan should turn on. the conditions that turn it on are either coolant temperature, or A/C line pressure. I'm guessing I had no problem when I had a warm engine because the fans were running. And likewise I didn't have a problem when I had a cold engine and immediately drove the car since air was moving across the condenser.
So, the question now is where in the world do I start. Since I know the fans run when the engine is warm Relays are likely good. I have an OBDII Bluetooth scanner on the way that I can use with software on my Android phone or laptop. I'm hoping it will allow me to read sensor data Like maybe the A/C pressure reading. My guess is to start at the sensor and work towards the fan relay. From what I can see the A/C pressure sensor feeds into the PCM which I'm guessing controls the fans based upon a logic circuit inside which has the parameters for fan operation. Looks like I need a test procedure for the A/C pressure sensor and go from there. I'm going to look that up and see what I can find. My thinking also is that the pressure sensor should cut out the compressor clutch if it senses pressure beyond a preset value but I don't know. I'm thinking that if it were working properly then it would cut out the compressor before pressures got high enough to blow the relief valve.
What does anyone think? Does it sound like I'm heading in the right direction?
Just change the pressure transducer with a junk yard unit - that's the best way I can think of to test it - but there may be others. If you take the transducer off, it un-threads - unscrew it quickly so you minimize pressure loss. There is a valve behind it so that it doesn't drain when you have it off. Then install the new one and try it out.
I just found someone with the same model and year vehicle with an identical problem.
I have a 02 Chrysler Concorde that is about to drive me crazy. I recently had to do some repairs, which included replacing the condensor, accumulator, & the evaporator. In the process of making the repairs, I flushed out the remaining hoses/lines to make sure nothing was in them.
Before re-charging the system, I pulled a vacuum on the system to check for leaks ....didn't see any issues. I started the vehicle, turned on the A/C & and began to charge with freon. The compressor kicked on as I expected it to do, however I noticed neither radiator fan came on. I realized the engine had not heated up yet, so maybe the computer hadn't found a need to activate them. The one thing I noticed is that the high pressure side of the compressor started to get pretty hot. Took a while to get the first can into the system(12 oz). After the engine ran for some time, I began to charge the second can. The compressor's pressure relief valve (mounted on the rear) spit out a burst of freon and then re-closed. I felt the rear pressure (high side) again and noticed once again it seem hotter than what I thought it should be.
i then checked the fan relays by replacing the hi/low one and then the hi fan relay......as I had a few extra ones on available. No change......fans still not running. By this time, my temperature gauge was half way up the temp scale and holding.
During this time, the a/c didn't really feel very cool. I "thought" that at minimum, one of my cars radiator fans should be running. Smart or not, I removed the hi speed fan relay and jumpered it to make it run. Immediately, the a/c air became cooler, the freon charge on the second can went in so much better.
With all of this being said, I wanted to know when my radiator fans are supposed to come on. Which sensor contro their operation, is it possible for the temperature gauge to read correctly on the inside of the vehicle and have another temperature gauge issue that would not allow the fans to cycle correctly.
I am positive I do not have any restrictions in my system, but from what I can see, the fans aren't coming on........to pull air through my condensor....therefore causing the freon to heat up too much which increases the overall pressure.
Help! I am at a loss as to what I need to do to check and see why this car is not activating the high speed fan relay.
Any assistance would be greatly appreciated.
I'm going to check into replacing it. So you can change it without evacuating the system?
Yes, that was the problem. Just went out and pulled the support that sits atop the radiator and grill, removed one side of the radiator hose. Pulled the connector off and one of the pins came out with the connector the connection on the sensor was full of corrosion. DEFINATELY defective!!! No doubt about it!
New sensor in, recharged, and working good (so far). I have to wait for it to get cold so I can check for cold fan operation with he A/C on. The new connector I got with the sensor which was solder and snapped together was a little Chinsy and didn't stay snapped together. I had to monkey around with some needle nose and pull the pin sockets back out after the socket fell apart while trying to push it on. Here is what the old sensor looked like.
you can see the corrosion and the missing pin (supposed to be three).
Last edited by Mariner; 10-10-2012 at 04:11 PM..
Reason: more info