I have a 91 with the electronic climate control. Well, the air blew warm and there was a error code #9 on the unit saying there is low freon. Ok, simply enough, I went to the parts store and bought a 134 conversion kit and put the fittings on and saw on the pressure dial that in fact it was low so I put in the recommened 45 psi in. Well the a/c still doesnt work. The compressor kicked on and off about 5-6 times but only like 2 seconds per interval. Why is this happening? I even have a shop service manual and it said to clear the code in the system, but I took off the battery terminal for a minute and put it back on. Still nothing. Does the A/C cluch have anything to do with the radio system either? The reason I ask is I have the fuse out for my radio until I get the amps fixed in the front as they are screaming. Is there anything else I can try or do? I figured it would be simple.....but as everyone knows.....Vette's just love to be difficult. Any help would be greatly appreciated. Thanks

 

One possibility:

There's a filter-type orifice tube, which might very well be clogged. Calls for a discharge/recovery of refridgerant, removal and replacement of the orifice tube ($20), and re-charging the system. About $90, IF that's what it is.

https://www.corvetteforums.com/m_37418/tm.htm

 

You know it did mention about that orifice tube, but where is it on a 91? How do you remove itand is it a special part from GM or can you buy it anywhere? thanks

 

Its possible that the low presure switch went bad.I had to replace mine.

 

where is the low pressure swich to test it?

 

it did recognise the boost in freon pressure on the low side and activated the a/c clutch but it onwas engaged for maybea second then back on again for about 6 times, then nothing ever again and the air was still warm. Also even after I put the freon in and reset the battery it still said low freon on the unit even though the gauge was telling me there was plenty. Then manuel said to put in 45 psi, as soon as it did hit 45 thats when it engaged but not for long. thanks for the help..

 

Hello,
The minimum requirement for changing an R-12 system to R-134 is (assuming the system is in good working order):
[ul][*]Recovery old refrigerant[*]Replace receiver / drier or accumulator[*]Drain as much oil from the compressor as possible[*]Add the correct amount of oil back into the system[*]Vacuum system to remove moisture[*]Add the recommended amount of R-134[/ul]
This procedure will provide long term results if done properly. Anything less than this and you will be working on the A/C system in the near future. More than likely, the first thing to go will be your compressor. If you vent / recover the R-12 and just add R-134 you will starve your compressor from lack of lubrication because R-134 is not soluble in mineral based oil, which is what R-12 uses.

Go to the automotive A/C forums (a/c kits.com) and do some research. This is where I learned a lot.

CG

 

Speaking of A/C problems...I had some work doneby a local dealer on my '95 when it would not blow cold. I just don't have the facilities to do any work myself. Turns out there was a leaky fitting. Even after part replacement, system pressure checks, and re-charge, the A/C takes forever to cool down the cabin. The A/C in my SUV cools the entire SUVcabin down in minutes. Is this a function of lousy A/C in a 'vette, or do I need to have it checked again, as in the entire climate control system? Welcome to the club!

 

My money is on low pressure switch. It is screwed on the accumulator with a 2 wire connection. Have changed out tons of GM low pressure or cycling switches as it is called. Very common problem on GM's. Your ATC control head looks at the continuity throught the switch. Also, some GM's, you have to disconnect battery for a minute to reset control head.

 

Ok, I bought a new orifice tube and installed it with no problem. Disconnected the battery and charged it while the car was off (like the gm service manual said) to 45 psi. As soon as I reconnected the battery and started the a/c, once again the compressor kicked on like 8 times withit only running like 2 seconds each time within a minute. It then kicks back a code into the electronic control a code 9 which is low refridgerant which there isnt. Very weird. There are no leaks present. The heater and everything works fine so I dont think its the A/C programmer. By the way, I didnt have to add muchr132 to it toget to 45 psi. Does that sound right? Only like a half a can. I give up.Any other suggestions?