Air Conditioner questions

[BrentS]

The other day, I got the "Low Refrigerant" warning on the CRT, and it seemed to set a B446 code.
My mother (original owner) gave me the car in 2006, and I have had no problems with AC until now.
I don't believe she ever had it converted to R-134a. I vaguely remember her needing to get some added, either once or twice, many years back....but basically the system has worked well.
Since I have very little knowledge on auto AC systems, where do I even begin? Are shops still able to add R-12?

[padgett]

1) R-12 should still be available, demand is dropping since has not been used in new cars for 20 years.
2) If it had been converted, the fittings should have been changes and a blue sticker put under the hood, if not it may still be R-12. Good tech should know.

[BrentS]

Ok, I'll take a look.
Is there something that's worth trying before I bring it in? Could I add refrigerant myself?

[Mc_Reatta]

Not having to touch the AC system in 6 years is amazing, especially if it's still the original compressor.

Given you are just getting the low warning and not the very low warning (B447 or 448) you can probably get by with just topping off the refrigerant.

For you to do this yourself, you would need a can of R-12 if that's what you still have, (available on ebay or craig's list), a can tap, and a low pressure gauge.

If you don't have any of these on hand, or have a friend you can borrow them from, it would probably be easier and about the same price to have a reputable AC shop to do it once for you. That's assuming that you are just a little low on freon.

Without using a low side gauge to see it's hard to know for sure.

[Howard]

If your car has been converted to 134A, recharging kits are available at most auto parts supply houses. If your car still has R12, then things become more difficult. One can no longer buy R12 at parts houses unless you have an A/C license. R12 can be purchased through sources as eBay. eBay would also be a source for the old Manifold Gauges required to put R12 in the system. My advice would be, leave everything to a trusted mechanic if you are unfamiliar with A/C systems. As an aside, there are two low A/C warnings. If the car is low on refrigerant a warning is displayed on the screen and a code set. Recharging of the system is possible during a low refrigerant warning. If a warning is displayed on the screen that the refrigerant is very low, the compressor has been disabled. The codes will have to be cleared before the A/C can be charged. Some people are unaware that a very low refrigerant condition turns off the compressor. I had one mechanic tell me my compressor was shot and needed replacement. I went to the car, cleared the code. It was clear that nothing was wrong with the compressor.

[BrentS]

Yes, I'm positive it's the original AC compressor. I believe it was topped off, when my mother owned it from 1989 to 2005-ish.
I only saw B446 code, and I believe the compressor was still running, air was still cool.

More Q's:
1. Is it worth doing the conversion to R-134a? Or, is that expensive, or will that open "a can or worms", etc.?
2. Is there a specific fitting that I should look at, to determine if it's still R-12. I just don't remember my mom ever getting it converted, and I don't see any conversion sticker.

[Mc_Reatta]

If you can get away by just topping off with some R-12 that's the way to go.

Only time to consider a conversion is when compressor needs to be replaced. And even then it is still possible (and possibly advantageous) to stay with R-12 depending on what needs to be done.
Look at the valve on the accumulator (round silver canister behind radiator between engine and inner fender) and see if it has threads on the end and looks like the valve stem on a tire (R-12) or it looks more like the one in the attached photo (R-134a) Photo is for the high side but low side looks very similar.

[Howard]

I agree with Mc_Reatta, if you still have R12 in your system and the A/C components are still OK, go with the R12. At about 145,000 miles, my A/C compressor bit the dust. It was replaced and the system converted in 134A. The total cost of labor, compressor, and everything else was about $800.00. After the conversion, the car was still cool and the unit seem to work as before. Did it get as cold as with R12? No. With R12 temp at the vent was about 38 degrees. With 134A the temp at the vent was about 42 degrees. Not a lot of difference. The summers here in Southeast Texas are not cool. In point of fact, as I write this, it's 97! Even with the 134A conversion, the car did cool down, even in Texas. If your A/C system is good otherwise, I don't see any reason to switch it to 134A.