Air Conditioning Conundrum

[SteelBlueZR1]

Has anyone had their air conditioner work perfectly one day, and then the next day go from blowing cold for a half a minute and then only hot air? There are no codes in the auto a/c display, just shows -00.

When the car is stopped now, and I turn on the A/C to Auto the idle speed does not change, nor do I hear the A/C compressor clutch engaging. My 1991 ZR1 has just 8,000 miles and the A/C has worked perfectly before yesterday?!

I have pulled the A/C, Radio and Courtesy fuses, but that did not help... I would expect to get a low freon code if this was the reason for the compressor not engaging?

I am going home to read the A/C Solutions from our site, but wonder if this sounds familiar to anyone, so I can fast track a diagnosis and repair this before Corvettes at Carlisle this weekend?

Does anyone know where I can have the A/C recharged/tested/repaired with R12 refrigerant in Maryland... or does WAZOO have a stockpile of the old stuff

[-=Jeff=-]

Has anyone had their air conditioner work perfectly one day, and then the next day go from blowing cold for a half a minute and then only hot air? There are no codes in the auto a/c display, just shows -00.

When the car is stopped now, and I turn on the A/C to Auto the idle speed does not change, nor do I hear the A/C compressor clutch engaging. My 1991 ZR1 has just 8,000 miles and the A/C has worked perfectly before yesterday?!

I have pulled the A/C, Radio and Courtesy fuses, but that did not help... I would expect to get a low freon code if this was the reason for the compressor not engaging?

I am going home to read the A/C Solutions from our site, but wonder if this sounds familiar to anyone, so I can fast track a diagnosis and repair this before Corvettes at Carlisle this weekend?

Does anyone know where I can have the A/C recharged/tested/repaired with R12 refrigerant in Maryland... or does WAZOO have a stockpile of the old stuff

good luck with finding r12..

my best guess is you have a leak on the High Side. my Old GTP took a rock or something in the Condenser and I would charge it with r134 and it would be gone the next day, found out it needed a condenser

[secondchance]

Bert,

Tank to Kevin w/ black Z. David should have his contact info.

[scottfab]

Since there is no low freon code set I'd concentrate on the notorious contacts on the AC control unit. Clean with pencil eraser then coat
with dielectric grease and reconnect.

[SteelBlueZR1]

Thanks everyone for the great feedback and ideas... I can't imagine the compressor or compressor clutch is bad, given the low miles and minimal A/C use... Yun, I will get Kevin's number... Scott, I need to take off the power key radio bezel and replace it with the new one I just found, so I will clean the contacts, however, the A/C control unit has always worked fine...

Any other ideas on why my compressor won't turn on, when I have no Codes in A/C control diagnostic for low freon?

When I went into diagnostic mode, the "compressor on time" showed 0 when in Auto mode (A/C System Mode = 02)., so the compressor is clearly not turning on. Also, the "temp door position" was Full Cold (253), so I don't think it is a control unit issue...

[Hammer]

Pull the battery negative for I think 5 or 10 minutes. Resets the cooling head. Does it work now?

If not, pull the low pressure cycling switch and jump the connector. Does the clutch work and does it blow cold now? Could be that switch.

You can also pull the fan switch connector, that's the rear one of the two on the high side line along the passenger side frame above the shock. Did both fans come on? The secondary fan MUST work or the AC won't. It controls the pressure.

That's it for me. Others will have to chime in now.

[Hammer]

Any updates yet?

[SteelBlueZR1]

I'm at Carlisle and Kevin will be bringing his gauge to check the freon levels. I will pull the battery once I park at the infield and see if that resets the cooling head too... Then check the other items you mentioned. Thanks for the help Hammer... I guess you are not going to make it to Carlisle by way of Idaho?