CFeria

What's up, I am new to the forum since I recently purchased a 91 Vette, have tried searching for my answer but was not able to find my answer. Although I think it is some what common sense I thought I should ask to be sure.

My problem is I need to add r134a to my ac system, it was converted by previous owner a few years ago. Now the outside temp has been between 45*-57*. When I hook the can of r134a onto the low pressure side of the system I purge the air in the line by opening the valve slightly before snapping the quick connector on, start the car, set the ac to max which is 60* then go back under the hood to open the valve on the can of r134a I notice the compressor never turns on, so I am guessing this is why it never takes in any of the r134a from the can.

Could this be because the system see's the temp has already been reached since it is about 57* outside so there is no need to start the compressor to cool the interior of the car?

Any help highly appreciated!

Thanks!!!

SunCr

Ambient Temp is part of it, but why do you think it needs any gas? Best to hook up a Manifold Gage set to see what the static pressure is first. At your temps, pressure should be 49 to 52 psi. It takes 50 psi to close the contacts in the Low Pressure Switch so some engine heat should get the compressor cranking if there's any gas in it. Once it's running, it'll keep turning until the Low drops to 25 psi at which point, the Switch will open and cut power to the Clutch. Assuming you've got at least 49 psi on the Low, I'd let it heat up and see what it does while monitoring gages. Then to put gas in it, you can jumper the Low Pressure Switch Harness contacts with a paperclip which will keep it running while you add gas. Recheck when it's warmer, like 70 or better, because it's really easy to cram in too much when you charge at these temps.

92vetterob

If your climate control is flashing it usually indicates low freon code 09, once this code is triggered it shuts the compressor off...you need to disconnect power at the battery and reset the computer, once reset the compressor will begin to cycle on and off quickly, act fast while this occurs and begin adding freon to the system. As you add freon to the system the compressor will stop cycling on and off....this is what I did on my 92

Rob

CFeria

Thank you so much for the replies, I do need to get a manifold gauge set, and plan to, reason I was trying to add r134 is because the climate control was/is flashing. You are correct it is code 09 low Freon. So just by adding Freon dosent clear the code? I need to disconnect the battery to clear the code? Thanks much this is my 1st vette, I came from owning a rusting, and I made the switch b/c had trouble with my 2009 GT and Frod was of no help even though it was supposed to be covered by warranty!

THANKS AGAIN EVERYONE!

92vetterob

No problem found the answer on this forum as well

SunCr

You won't get (much) gas in it if it's cycling and it can do two things: Re-set the Code and shutdown; AND allow any gas that's in it to flow back into the Can which can cause it to blow up and hurt you. Jumpering the Low Pressure Switch after you have cleared the Code will keep it running and keep you safe. The only other danger is that oil has escaped with the gas and without enough oil, you can grenade the Compressor. Fortunately, those explosions are usually self contained. Unfortunatedly, what's left inside the system means a complete rebuild. Look on the hood above the Compressor for oil. If it's there, it needs a new shaft seal which you should fix before trying to re-charge it. That way, you'll get the right amount of oil back in it.