Thanks in advance for your assistance! I have a 1988 Cadillac Sedan DeVille. The car is in excellent condition and was well maintained by the previous owner before I purchased it last fall. The A/C was converted to R134A before I purchased the car, and the system cooled great. This summer we had several days of record heat. On one of these days I decided to drive the Caddy (I don't drive it much). It did not cool as well as I had remembered ... but I thought maybe it was the extreme heat. Several days later I checked it again, and it still was not cool. I could hear the compressor kicking on, but no real cooling. I called a local shop to make an appointment for a recharge/inspection of cooling system. On the way to the shop (about 25 miles), I turned on my A/C to see if perhaps highway driving would assist in the cooling process. At some point during the drive the ECON light came on my A/C, not AUTO. When I tried to turn the A/C back to AUTO (maximum cooling), it immediately shifted back to ECON. In other words, I could not turn on my AUTO (cooling) A/C. I got to the shop, and the mechanic tried to charge my system. The compressor would not come on to take the charge. He tried again and again - no compressor kicking on. I looked in the manual and learned that on the 88 DeVille the Service A/C Light will come on after turning the ignition to warn of low freon or needed service (mine started coming on at the mechanic's) and that the system will shift automatically to ECON to prevent damage to the compressor (that is what is happening now). My mechanic is not familiar with the 88 Cadillacs -- and I don't know what to do. My questions are these: 1) Is there a reset process for the compressor to kick on so that the system can be recharged and 2) how do I know if my compressor is fried or not since it won't come on? Any advice on what to do would be appreciated. I have never had a problem with this car, and I just want to make sure I repair and/or service the A/C correctly and thoroughly. Thanks again.

 

it is a standard GM unit. call another shop that knows how to charge after a
shut down. i believe they go through the low pressure side, but that is a guess.

i dont think the compressor will start until the pressure is above the minumum.

 

Hey T-man: Just a thought, maybe your system has a faulty ambient temp. sensor or the in car sensor. They are both in the same circuit so worth checking out. Good luck.

 

The econ light indicates that the compressor has been turned off. the codes have to be cleared after being re-charged before the compressor will turn back on. Hold the off and warmer (red) button until all light light up on the display, after that I really forgot how to clear the codes. you will have E codes and F codes off and cooler may clear them

 

Also i have seen quite a few problems with switching these cars from r-12 to r134a. Check to see if there is a muffler on the high side. if there is then we usually took out the orfice tube to correct the condition