A/C not working disgnosis question.

[delorean928]

My A/C is not working no matter the seletcion I make on the A/C panel. The clutch of the compressor never engages. I checked the high and low pressure switches and the one mounted on the accumulator (i believe it's the low) is open. I tried applying 12v directly on the compressor and waited long enough to see that the air never comes out cooler :( Am I at the final step of the diagnosis and I must simply have the system pressure checked? Is my test effective?

[Bitsyncmaster]

You probably have no freon. The low switch must be closed for the compressor to run.

[delorean928]

You probably have no freon. The low switch must be closed for the compressor to run.

That's what I think too. Is it still easy to have these systems refilled with Freon today? I believe it was R-12? Will I need a conversion of some type?

[Michael]

Jumping switches and forcing the compressor to spin with no freon or oil can do some damage. The very first step in diagnosis is put the gauges on it. If its out of freon (which it probably is) it wont take long to figure that out. If it is out, you will not need any special fittings as long as you have the factory 12 service ports. You will need a r12 machine and those are becoming hard to come by. Even most shops dont have them. You should first pull the system down and make sure it holds vacuum before doing anything. Then if it's been dormant for awhile, replace the accumulator and the high pressure switch while you are already there and they are cheap. I would also replace the orifice tube and service valves. Then flush it, oil it, and charge it. Remember if you plan to use the Freeze 12 replacement then you will use 10% less than what the system is designed for with R12. Most oils today are universal but just make sure it's OK for r12.

If you are lucky it will work like a champ but don't be surprised if something goes wrong in the first month. Old AC systems that have sit empty tend to throw you a curve ball when you wake them up.

[delorean928]

Thank you for the help Dave M and Michael. I'll check that with the freeze guy :)

[DMCMW Dave]

That's what I think too. Is it still easy to have these systems refilled with Freon today? I believe it was R-12? Will I need a conversion of some type?

R12 is more or less impossible/illegal to find Canada. Your A/C man will either want to convert it to R132 or Hydrocarbon Refrigerant (RedTek). RedTek is legal/encouraged in Canada and seems to work very well.

[delorean928]

R12 is more or less impossible/illegal to find Canada. Your A/C man will either want to convert it to R132 or Hydrocarbon Refrigerant (RedTek). RedTek is legal/encouraged in Canada and seems to work very well.

Do I need something special to convert my a/c system to RedTek? :(

[DMCMW Dave]

No. It is an easier conversion than r134

[Ron]

...replace the accumulator....Then flush it...
$.02
Flush first!

[NightFlyer]

I'll be converting my car to 12a (RedTek) in a couple weeks. The steps I plan on performing:

1) Back-flush the system.
2) Vacuum the system.
3) Fill the system with ester oil and .77 pounds (12.32 ounces) of my 12a product.

Should be relatively straight forward. I don't plan on changing out any of the components of the stock/OEM system that's currently on my car.

The reason I'm doing ester oil instead of mineral oil is that the 12a product that I'm using, FrostyCool, warns about this:


FrostyCool 12a Replacement Refrigerant along with mineral oil are incompatible with butyl rubber hoses.

While I'm not sure of the exact type of rubber found in the stock system, I figure better safe than sorry.

Anyway, I'll post a thread detailing the steps I take and the results that I experience :smile:

[delorean928]

Here it is finally ice cold A/C :)
My specialist checked for leaks and saw nothing wrong. He just added R132 and a sealer. My compressor already had the R132 adaptors confirming it had already been converted so it has'nt been complicated.
thank's to all for the help and infos