QuestionQUESTION: I am trying to locate both the high and low (if both are used) A/C switches on a 1988 Cadillac Brougham. The A/C compressor is not cycling (I have a professional code reader/diagnosis tool from that era which seems to be telling me the system is calling for A/C); however, the compressor still does not cycle. I have a few cans of R-12 left - however, I do not know if the system is low on refrigerant. I think it may be low so I wanted to cross the leads on the switches to check and see if the switch was the issue. Fuses checked. Any other ideas would be appreciated.
ANSWER: OK, On top of the big black plastic cover housing which is located behind the accumulator (receiver/drier) you will see 3 electrical components. The closest one to the front has 2 wires which are colored BROWN and BLACK.
With the engine running, disconnect these 2 wires from the PRESSURE CYCLING SWITCH and check with a meter, NOT a test light to make sure that the brown wire has battery voltage. If it does, with the electrical connector still disconnected jumper the BROWN wire to the BLACK wire and see if the compressor engages. If it DOES, You are most likely low on freon (refrigerant) or you have a faulty cycling switch.
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QUESTION: I saw the connector - I jumped these two wires; however, now I have a new problem. Prior to this...the digital temp indicator was working, the "Auto" low/med/high was working with the fan blowing air - since I jumped those wires - now the 20 amp fuse to the A/C circuit keeps blowing...the fan quites and the digital a/c-heat control looses power. When I unplugged that wire from the unit - it no longer blows the fuse...could jumping those wires have shorted something in this circuit?
ANSWER: You stated you jumpered the 2 wires. I told you to check for BATTERY VOLTAGE at the BROWN wire of which you apparently did NOT do.
Therefore you either blew the diode at the compressor and or blew the ECM computer.
If you are mechanicaly inclined or know of someone who is, You will need simple electrical schematics, Test procedures and picture locations of the components within the system that is causing you problems of which can't be done on this website which only allows one picture. I do not have a website so you will have to e-mail: onlineautohelp@msn.com in order to obtain the information.
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QUESTION: OK...now that I have removed my head from my behind [:)] and actually read AND followed your directions EXACTLY instead of half reading what you said: You said "make sure that the brown wire has battery voltage. If it does, with the electrical connector still disconnected jumper the BROWN wire to the BLACK wire and see if the compressor engages."..........The brown wire did/does have voltage (13.7 v)...however, I went ahead and check the diode at the compressor to be sure my ignorance didn't blow it (pos/neg = 0v / neg/pos - .471v).
Then I used a jumper wire (with an inline fuse) and jumped the black/brown wires - the compressor CLUTCH does engage; however, the compressor does not turn-the clutch just slips and squeals.
I'll assume this mean the compressor is frozen...but I'll defer to the expert because I am clearly no expert.
If it is the compressor - can I install a new compressor and have the system evacuated then re-install R-12 (have 3 12oz cans left - I believe it takes 3.5 lbs, so I'll be a bit shy of a full charge) or am I going to find NOBODY will evacuate the system for me since it is R-12?
Thank you for your assistance.
It is greatly appreciated.
AnswerDoes all the items that you previously stated did NOT wirk when you did the iniyial jumper wire connection, Work OK now ?. Does the blower work oK ?.
Yes, It definately sounds like the compressor is frozen and there is way to many things to do before you install the compressor. I STRONGLY suggest that you do NOT attempt this yourself.
