So.... when I first got my 79 5 years ago, the A/C did not work.  I think the following summer, I put the R134 connectors on it, and shot it full of R134.  A/C worked.  I must have gone the next few summers without it, because it stopped working again and I just never got around to shooting it with more R134. 

So, with my impending trip to Pigeon Forge less than 1 week away... and considering the temperatures in PF will be up there, I figured I'd go pick up a new can of R134 and shoot it in.  Well... I got the can and as luck would have it... where the fill connector is, it is right up against the compressor support and the connection from the fill hose would not fit!  I won't bore you with details.... but I wound up getting an extension hose and that worked.  I shot some R134 in there.

Still, no A/C.  Compressor never turned on.  I called my personal phone support (aka kstyer) and he helped me diagnose the problem.  Again, I won't bore you with the details, but after about 12 phone calls to Ken, and a couple of trips to the store, he helped me determine that the A/C compressor clutch was broken.  So, I was left with a couple of choices... replace the whole compressor w/clutch, or replace just the clutch.  Ken told me how to do just the clutch, but I decided I just don't have the time, patience or correct tools (that I could rent) to do it.  So I decided to take it to a mechanic.  The next trick was to find someone capable of working on my Vette, on such short notice and have only 3 days to get 'er done. 

So this morning, I found a little shop within 10 minutes of my house that actually specializes in Vettes (among other things). The owner has 4 Vettes himself.  He said he could get me in today, but he'd have to replace the compressor and clutch, because he doesn't have the tools to do just the clutch.  I figured, with me running out choices and time, I'd let him do it.

Ken had warned me that once I got the clutch (and compressor) replaced that that may not be my only issue.  During our diagnostics, we were not getting power to the compressor, even when the A/C switch was on on the console. 

I spoke to the shop just a little while ago...they replaced the compressor/clutch.  Charged the system. Still no A/C.  And just as Ken suspected, the clutch only kicks on when they jump it.  So now they are on to tracing the electrical issue.  (can you say $$$$).

More tomorrow....  Keep your fingers crossed for me that they find it, quickly!  And that I'll have nice cold A/C for my trip to PF.  2 days left, and counting!!!!
Adam38887.5869907407

If the  compressor clutch engages when they jump it, I assume you mean they are unplugging the lead from the pressure switch and jumping across the plug, the the first problem may be the pressure switch. A very common problem.
They need to check for voltage at the compressor before and after jumping the terminal. If the clutch is engaging and the compressor is turning and it is still not cold then they need to look for a blockage or moisture in the system.

I just went through this process myself, with Ken's help, and my 75 will now run you out of the cockpit. I am confident yours will do the same in a day or so.
Scott
ranger338887.7834027778

Scott, How deep did you have to go to get your AC to work that well ? What did you replace ? I'm trying to get mine working (It's still the orginal Compressor, I think) Do I convert or start with a new up to date Compressor ?

[QUOTE=
I just went through this process myself, with Ken's help, and my 75 will now run you out of the cockpit. I am cinfident yours will do the same in a day or so.
Scott

warbird38887.7284606481

If the compressor engages when the pressure switch is jumped, the switch is bad, or there is not enough freon in the system. Jumping the pressure switch tells you it has power, so there should be no other electrical issues, other than the pressure switch.
If they have to power the compressor from somewhere else, then you have more diagnostics, aka:$$$
Hey, I'm drivin in from Texas with no A/C...buck up!!

Warbird,
If you are still running an R12 system then you sould definitely convert to R134A. The cost of R12 is extremely high and you need a license/certification to buy it.
I had to change the hose assembly that runs between the receiver, compressor and evaporator. I also changed all of the o-rings when I had it apart. My compressor was okay but the pressure switch was bad so I also replaced it.
Once it was all assembled I pulled it down with a vacuum pump for about 45 minutes to get all of the moisture out of the system. Ken said that this is very important because if there is moisture present in the system that it will not cool properly. Once it was pulled down I then introduced the R134A, through a manifold guage set, while the car was running and the A/C was on high. I filled it with about 2 lbs. of R134A and the low and high pressure was at the values that Ken specified.

After it was fully charged it was blowing at 34-36 degrees at the vents. The vacuum pump and manifold set also shows you the condition of all the hoses and seals. If it will not hold the vacuum, then it is leaking somewhere.  I hope this helps. I could not have done this job without Ken's advice and wisdom. I still owe him a tall iced tea.
Scott
ranger338887.7949074074

Here's an interesting article about R134a but it could be BS for all I know.

http://www.deadly134.com/

WOW!!
I guess you can post anything you want on the net!!
I call BS on this one.
A break in an A/C line as the result of impact/crash would release the refrigerant almost instantly. It would not contribute to keeping a fire going long enough to burn a car to the ground.
Strangely enough, I can't remember reading, or otherwise hearing of a massive amount of deaths while driving a car with a 134a refirgerant leak. If this is true, then all of the automakers on the planet are due for some wild lawsuits!!
134a is as safe as any other refrigerant we've ever used in autos, and safer than some of the "blends" some folks have on the market. Can you say "propane"?

Thanks Scott, We still have some R12 at work, but I should switch over. Once I get the project done I'll post an update.

Cookie

I charged mine up on Sunday just to make sure it will be nice and cold. It works great, lets hope it stays that way. I hope you get yours fixed in time, I have a feeling we are going to need it.         

Dave

DaveM38888.2780671296

They called me a minute ago...

It's fixed!!!

The compressor (clutch) was definately shot. So compressor was replaced.
Two wires had to be repaired, to and from the pressure switch.
And the pressure switch had to be cleaned up.
Filled with R134A.
...It's blowing cold!!!

Cost me 500 and change, but if it works, and it stays working for a long time, it'll have been worth it!!

I had asked them to also change the oil while it was in there, but they didn't do that yet... so I asked them to before I picked it up...and when I asked how much that would cost, they said "don't worry about it".  Also asked them to check the air in the tires. 

I can pick it up tomorrow and should be all set for Thursday!!! I'm so excited!

btw, name of the shop is Trappe Auto in Trappe, PA.  So, I'd recommend these guys!!  Like I mentioned, one of their specialties is Vettes... and currently, I believe it!