Goodmorning, we inherited this 92 Bonneville from my late grandfather 3 years ago and it had no AC. I took it to a shop and I knew because of the age of the vehicle the old refrigerant had to be vacuumed out, we also had the new fittings placed on so that future maintenance and aftercare would be simple. So after reintroducing the system to new coolant and new fittings all was well with it. My mother used it in between her daily for the last few years no problems. Last month my mother told me that the Bonneville wasn't blowing cold and it was beginning to be unbearable (were in Phoenix, AZ), I am not a mechanic so, I told her it lasted nearly 3 years which isn't a surprise and it probably needs more coolant. I got it last week, cause I'm in between vehicles as we just sold our family van and, she is right it is unbearable. A few days after I was using it the AC kicked on, blew really cold and I was ecstatic with joy. After I parked it a few hours later and attempted to see if the AC was still working I was met with disappointment to learn it wasn't anymore. So im curious, if it blew cold then it has refrigerant, is it possible it is a AC Switch ?. The Bonneville has a few AC switches but, where do I start ? I was looking at the AC Switch :Cooling Fan refrigerant switch and possibly starting there? any other helpful info would be greatly appreciated. I already purchased the cycling switch and Hi switch but have yet to install. Thank you for your consideration in this matter.

One thing to check could be the AC relay. Might be sticking. Look under the maxifuse relay center cover. The relays will be labeled somewhere in there, maybe on the underside of the cover. Swap the AC relay with another one (they are the same) and see if it starts working.

I can't be of help with the pressure switches.

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WHITE WHINE - 1992 SSE Supercharged 236.26 ci (.040 Over) 15.090 at 90.2 MPH on old engine w/ slipping trans & melted O2 sensor - Gen 3 M62 and matching TB, Gen 2 Pully, Zillamotorsports Ported LIM, YT 1.72 Roller Rockers, SII FPR & Injectors, Hypertech Thermomaster chip w/ 160 Thermo, TransGo Shift Kit, Infinity/Pioneer Speakers & a 10" Alpine Type R Sub, all the watts, 140 amp Alternator, Ricepipe CAI w/ heatshield, Pilot Angel Eye Foglights, Clear Corners, '02 17" Chrome Bent 5's, Magnaflow F-Body Muffler and Hi-flo Cat, Ceramic Coated Ported Exhaust Manifolds, Fan Override, Monroe Reflex struts, red calipers
2009 G8 GT - Sport Red Metallic, loaded, SOLO Axlebacks, Rotofab Intake, Tuned, autodim mirror, removed intake manifold cover, HSV GTS triple gauge pod, two tone red-hot shifter and HSV SuperSport steering wheel, GXP rear sway bar and diffuser, 3.45 diff and various Camaro suspension bits, LED Taillights

here is a manual for a 93... should be same as 92

https://my.chevrolet.com/content/dam/gm ... owners.pdf

page - 268

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poverty forces one to do unorthodox things

2000 SSEi
past rides:
1996 SSEi
1992 GTP
1987 Grand Am

I would first check the pressures with a gauge set to be sure they are in spec - dont be hasty throwing parts at her without more diagnostics. do you have access to a good high-end scanner - may reveal issues with the head unit.

also, is the compressor spinning when it blows warm?

_________________
poverty forces one to do unorthodox things

2000 SSEi
past rides:
1996 SSEi
1992 GTP
1987 Grand Am

I don't know what you have for diagnostic equipment, but you can tell a lot from the behavior of the car.

When you turn the A/C on when there is an issue, does the compressor engage?
If so, does it stay engaged, or is it frequently engaging and disengaging?
What are the radiator fans doing? Do they kick on low and stay there? Does the main fan switch to high?
Does the engine idle up to account for the expected load?
Do you have Electronic Climate Control, or manual controls?

A real time data scan would definitely be helpful. It will immediately tell you the detected status of pressure switches, fan status, etc.

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~Randall~


1993 Buick Park Avenue - 197k - Some odds and ends done - Simply won't die
1994 Buick Regal - 78k - Bone stock - Always ready for a good kicking
1990 Oldsmobile 88 - Gone to a better place