This sad story is about my 2008 CVPI P71.
My A/C has been working great, until yesterday during the heat of the day. Went to gas station to fill up. When I was leaving I turned on the A/C and it blew hot air for a little longer than normal. I joined traffic and once moving, the air turned cool, then cold. Came to a red light and the A/C went hot. Once again when moving it started putting out hot air. This cycle was repeated until I got home. I assumed low on freon. Took the wife's car to my grandson's house to pick up my gauges, dropped by Autozone and picked a couple of cans of freon. When I got home I hooked up the gauges and got surprised. First - the engine was bogging down rather severely when the compressor kicked on. It would stay on very briefly (30 seconds?) and then switch off. This cycle was repeated while I was hooking up the gauges. I opened the low side and was surprised to see it almost pegged when the compressor was off and drop to about 120-130 psig when the compressor kick on. Opened the high side gauge and it was almost pegged when compressor was off and was pegged when on. I then also noticed that the cooling fan was not running.
At this point I thought the problem was about to be solved as I have two working spare fans and fan control modules. Switched modules first and none of them would start the fan installed on the car. I then brought out the other two fans and they would not run either. I then bypassed the module and found that all the fans would run with direct 12V applied. Found all the fuses that are related to A/C stuff on the internet. They were listed as: BatteryJunction Box fuses # 11, 21, 101 and 102 and CentralJunction Box # 8 and 15. My car did not have a #8 fuse, but everything checked as good.
So this morning I simply started over because I was stumped and quickly found that each of the fan control modules would now start any of the 3 fans. I think the only thing that is different is the temperature. It was well over 90 degrees yesterday and this morning it is a little over 70 degrees. Does anyone know what I need to look at now? I'm hoping it's something simple that I'm overlooking due to my lack of experience with the panther platform. My previous daily driver was a 1977 Mercedes 300D. I've alway performed all my own maintenance and repairs.
Stumped in Baton Rouge!
ETA - forgot to mention that the car never overheated during this adventure yesterday. At the time I really thought that perhaps the cooling fan was working once the car was underway. Is that possible?
My A/C has been working great, until yesterday during the heat of the day. Went to gas station to fill up. When I was leaving I turned on the A/C and it blew hot air for a little longer than normal. I joined traffic and once moving, the air turned cool, then cold. Came to a red light and the A/C went hot. Once again when moving it started putting out hot air. This cycle was repeated until I got home. I assumed low on freon. Took the wife's car to my grandson's house to pick up my gauges, dropped by Autozone and picked a couple of cans of freon. When I got home I hooked up the gauges and got surprised. First - the engine was bogging down rather severely when the compressor kicked on. It would stay on very briefly (30 seconds?) and then switch off. This cycle was repeated while I was hooking up the gauges. I opened the low side and was surprised to see it almost pegged when the compressor was off and drop to about 120-130 psig when the compressor kick on. Opened the high side gauge and it was almost pegged when compressor was off and was pegged when on. I then also noticed that the cooling fan was not running.
At this point I thought the problem was about to be solved as I have two working spare fans and fan control modules. Switched modules first and none of them would start the fan installed on the car. I then brought out the other two fans and they would not run either. I then bypassed the module and found that all the fans would run with direct 12V applied. Found all the fuses that are related to A/C stuff on the internet. They were listed as: BatteryJunction Box fuses # 11, 21, 101 and 102 and CentralJunction Box # 8 and 15. My car did not have a #8 fuse, but everything checked as good.
So this morning I simply started over because I was stumped and quickly found that each of the fan control modules would now start any of the 3 fans. I think the only thing that is different is the temperature. It was well over 90 degrees yesterday and this morning it is a little over 70 degrees. Does anyone know what I need to look at now? I'm hoping it's something simple that I'm overlooking due to my lack of experience with the panther platform. My previous daily driver was a 1977 Mercedes 300D. I've alway performed all my own maintenance and repairs.
Stumped in Baton Rouge!
ETA - forgot to mention that the car never overheated during this adventure yesterday. At the time I really thought that perhaps the cooling fan was working once the car was underway. Is that possible?
Well, it's fixed. It's been quite an ordeal. Here's what I found: The fan is turned on and off based on readings from the Cylinder Head Temp Sensor. This sensor is not in the coolant stream. It only reads the temperature of metal of the head. The computer then determines whether the fan should be on/off and what speed based on the signal it's getting from the CHT Sensor. This sensor in behind and to the left slightly of the alternator and under the intake manifold. I could barely touch it with 2 fingers. After lots of futzing around with it, I decided to try shortening a 12 point box end wrench. I figured I would at least be able to get that on the sensor body. I cut an old 19mm wrench down so the whole thing was a little less than 3" long. I was able to fit it over the sensor and then turn it 1/12 of a turn at a time. It was very hard to break it free and then a long slow process of 1/12 turn at a time.
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