QuestionQUESTION: Hello Tom,
94 Cadi Deville 4.9 v8
I emailed you a few days ago about my compressor not engageing..only works with a jumper on relay..Its not the relay because i switched them around (same ones)..the codes i got were ao12 you told me to change low side temp sensor but one i jumper it it didnt do anything should i still replace with new one..But Today compressor keeps going on and off every few seconds..freon was reading 50psi then it bounced up to a danger point i think like 100 psi then it went down then back up a little. today i cleared codes and
drove a few miles..Now the codes were
ao12 Current
ao48 History I dont know how this code was history it wasnt there yesterday i dont think i overlooked it..I know its for low freon but im pretty sure there enough in because it didnt drop lower than the filled mark on gauge Im just hoping it not the ACP..My skills are limited..
Thank you for all your help Steve...
ANSWER: Plug everything back in and with the ignition ON, Jumper the LOW PRESSURE SWITCH NOT the SENSOR. The SWITCH is located right next to the shock tower on the passengers side and listen for the AC clutch to engage with a CLICK noise. Or start the engine and jumper the switch and see if the compressor engages and let me know. If the compressor engages, You need to remove all the freon from the system, replace the orifice tube, NOTE: If the orifice tube is plugged with aluminum shavings this means that your compressor is on it's way out or that someone replaced the compressor and did not flush out the AC system and just left the aluminum shavings from the old compressor in the system which plugged up the orifice tube.
If you have a plugged orifice tube you will need to flush out the AC system and replace the orifice tube, Evacuate all the air from the system via a vacuum pump and check for leaks with a leak detector and if no leaks found, refill system with freon.
---------- FOLLOW-UP ----------
QUESTION: Hello Tom,
Thanks again for your help..
94 Cadi Deville 4.9 v8
Compressor keeps going on and off every few seconds continuosly.. I have ALREADY TRIED TO JUMPER THE LOW TEMP SWITCH and it DOESNT ENGAGE COMPRESSOR..ONLY STAYS ON WITH JUMPER ON RELAY..Should i still vaccum empty and check orifice tube? Im pretty sure theres no leaks..
NOTE:This promblem just started there was no indication like grinding or noise from compressor..
Thanks again Steve
ANSWER: Empty out all the freon, Replace the orifice tube, evacuate all the air from the system using a vacuum pump, jumper the relay and install your freon and remove the jumper wire.
---------- FOLLOW-UP ----------
QUESTION: Hello Tom
94 Cadi Deville 4.9 V8
Thanks for all your help! I swithed Programmer before emptying and Vaccumming just to see if it was electrical..Anyway I CHANGED THE PROGRAMMER AND A/C IS WORKING..Now im getting SERVICE ENGINE SOON and GETTING CODES AFTER I CLEARED AND ERASED.
PO 52 Hist.
PO 91 Current.
I Erased but they came back..DID I HAVE TO CHANGE (CHIP?) ONTOP OF ACP..It came out of a 95 Deville.. Steve
AnswerI honestly do NOT know if a 95 programmer is compatable with a 94 as I never use used pparts unless I am POSITIVE that they are compatable as it could lead to other problems.
P052 history = Cruise control vacuum solenoid fault.
Are you POSITIVE you cleared the "P" codes correctly as in 99% of all cases when the codes that show as HISTORY are properly cleared, They rarely return as HISTORY. They usually do NOT return at all.
P091 = Transaxle range switch signal problem.
Could be:
Faulty switch on transmission or misadjusted.
Faulty wire or wires.
faulty computer.
I can provide PICTURES that are NOT allowed on this persons website and simple test procedures for the codes if you e-mail me at: onlineautohelp@msn.com
