Cadillac Repair: 87 Cadillac Eldorado A/C, r 134 freon, r 12 freon

Question
My son recently purchased a 87 Eldorado and the original owner said he had had the old refrigerant change out for the new R-134 a few months before.  He said he had had a few Low refrigerant warning come but when reset all worked ok and the AC was cold. Recently though the warning comes on and and will shut down the compressor.  Could all the be because of the new refrigerant? I found this statement in an earlier answer. "You CANNOT use R134 freon in an R-12 system in a Cadillac as the sensors are NOT programmed for R-134 freon" Could this be causing the problem and what can be done to correct it?

Thanks

Answer
The statement that you quoted is MINE and YES the newer refrigerant causes the low side pressure switch to fault causing the compressor to shut down.


Your only solution is to switch back to the R-12 freon or keep resetting the computer ever time the low refrigerant warning light illuminates.