A/C help

[Murf]

Weather is finally warm here. Had the car out yesterday, 80 degrees + and the air conditioner worked fine. Took it out again today and nothing but warm air.
Checked the compressor, clutch engages when switched on and operates freely, fan goes to high speed on max. Don't have guages to check freon pressure. If I do have a leak, is now the time to convert to new style freon ( R-134?). If so, how costly is it. What needs to be replaced. Tried searching old threads, but no results.
Thanks,
Murf

 

[SKIP780]

just converted my 93 to 134a and it cost $142.that is the accumulater (dryer),conversion kit (seals,fittings),orafice and a seal kit for the compressor.i had a leaking comp.did the work myself and had a friend vacuum it down and recharge it.2 cans of 134a cost me $25>

 

[w8n4ya]

Weather is finally warm here. Had the car out yesterday, 80 degrees + and the air conditioner worked fine. Took it out again today and nothing but warm air.
Checked the compressor, clutch engages when switched on and operates freely, fan goes to high speed on max. Don't have guages to check freon pressure. If I do have a leak, is now the time to convert to new style freon ( R-134?). If so, how costly is it. What needs to be replaced. Tried searching old threads, but no results.
Thanks,
Murf

Hello Murf,

I hope this will help your dilemma...

I was experiencing the same problems, everything seemed to be operational, but the a/c only blew warm/hot air. After purchasing the 1990 Corvette Assembly Shop Manual for advice, the solution was simple. By disconnecting my negative terminal on the battery for 15 minutes, this caused the A/C Programmer to reset. After the terminal was reconnected, voila! It is the manual's 1st recommended solution to your described problem...not to mention the cheapest! It worked for me...I hope it works for you.

Now about the R134...on page 174 of 101 Projects For Your Corvette 1984-1996 by Richard Newton, he states,"I've never seen a retrofit to R134 that adequately cooled a C4. There's the simple fact that R134 is 10% less efficient as a coolant than R12 is". He continues, "There is so much glass in that back window that a system retrofitted to R134 can't cope with the heat."

I went with his advice and bit the bullet charging my system with R12. I agree, that as expensive as R12 is, it will cost more for a R134 conversion...with less cooling as a result. "More money for less effectiveness doesn't sound like a very good deal."

Of course, this is just one man's opinion...although a very experienced C4 man! He's had much more dealings with C4 ownership that I've had, so I heed his advice trying not to reinvent the wheel. I know you'll do what's best for you, your car and your budget and I hope this helped.

 

[Murf]

Thanks for the reply guys. Took it to my mechanic and found that the pressure switch had failed. R 12 charge was ok. Nice and cold again.

Murf

 

[88 4 Fun]

[QUOTENow about the R134...on page 174 of 101 Projects For Your Corvette 1984-1996 by Richard Newton, he states,"I've never seen a retrofit to R134 that adequately cooled a C4. There's the simple fact that R134 is 10% less efficient as a coolant than R12 is". He continues, "There is so much glass in that back window that a system retrofitted to R134 can't cope with the heat."[/QUOTE]

Even a fully operational R-12 system has problems due to the rear window area. I had mine tinted with a tint value of 18 and I used my dremal on the two inside center vents. I carved out the blanks in the vents to allow more air to flow through these vents. Made a big difference in the amount of air you get when you're in the bi-level mode.

 

[Bonnell]

Thanks for the reply guys. Took it to my mechanic and found that the pressure switch had failed. R 12 charge was ok. Nice and cold again.

Murf

I have an '88 and my A/C is good when it works but there are times that it simply will not call the compressor on. Today the A/C worked when I first started the car but then the compressor stopped and I drove drove 30 miles with no A/C. It does this sometimes and then the A/C will work again (compressor cools) after some period of time - it just seems to engage out of the blue after not working for 20 miles.

Any ideas? Anyone know where the pressure switch is located?

Any help would be appreciated.

 

[88 4 Fun]

I have an '88 and my A/C is good when it works but there are times that it simply will not call the compressor on. Today the A/C worked when I first started the car but then the compressor stopped and I drove drove 30 miles with no A/C. It does this sometimes and then the A/C will work again (compressor cools) after some period of time - it just seems to engage out of the blue after not working for 20 miles.

Any ideas? Anyone know where the pressure switch is located?

Any help would be appreciated.

Put a set of guages on the system and look at your pressures. Sounds like you have a low charge. Compressor comes on then off and won't run. Low freon charge cut out so the compressor doesn't burn up. It's oil lubed and freon cooled. No cooling it shuts down.

 

[TigerDale]

Hello Murf,

I By disconnecting my negative terminal on the battery for 15 minutes, this caused the A/C Programmer to reset. After the terminal was reconnected, voila! It is the manual's 1st recommended solution to your described problem...not to mention the cheapest!

Thanks w8n4ya , a quick fix on my AC using that method just made my day !

 

[brookman]

To dispell the myth - I live in AZ 110+ temps. I converted my system in my '88 to r134. As long as I am moving I can get 38 deg. vent temps. I am very happy with the results.

On a side note - you dont have to dremel out the center vents - the part that blocks the hole actuslly snaps out from the back. I did it to two of the 4 center vents and the extra amount of air is incredible.

 

[88 4 Fun]

On a side note - you dont have to dremel out the center vents - the part that blocks the hole actuslly snaps out from the back. I did it to two of the 4 center vents and the extra amount of air is incredible.

I looked at mine and I couldn't see anything that snapped to the back. Good tip though.

As for the r134a I'll retrofix once I run out of R-12 or my compressor gives out. When I bought the car the dealer had one heck of a time finding a clutch for this Niponaszio compressor or how ever you spell that company name. They said it was an $800 item and this was 5 years ago. You can find the compressors but the clutch are another story.

 

[Bonnell]

Boy did I get lucky. I was looking for a low pressure cutoff switch and I happend to touch a wire connector from the compressor and the clutch engauged and dis-engauged rapidly. I cutoff the bad connection and crimped on anew one and it works great.

 

[wilezcoyote]

A/C Compressor locked up today

:cry My compressor locked up while I was waiting on a light today. I started calling around to check prices. My question is this. What kinda Crack are these people smoke'in?!?!?!?!

Chevy dealer $1200

Eckler's, Mid America, Corvette America, etc... $825-900

Local parts houses $600-$1100 new & remanufactured

Advance Auto Parts $318 remanufactured
Their parts are of questionable quality in my experience

Is NipponDenso japanese for "Stick it to them"?

If anyone has any suggestions on other reputable parts vendors to check I'd really appreciate it.

Any donations to my Fix A Corvette Foundation* will be greatly appreciated

PayPal accepted

*monies collected will be used soley to procure corvette parts and beer.

 

[brookman]

I did considerable research on this when I thought mine was on its way out. The reason they are so expensive is that it is the exact same compressor they use on Porsche and BMW, plus a couple of other High dollar cars

 

[WhalePirot]

Is NipponDenso japanese for "Stick it to them"?

Ummmm, yes. Ever buy 'real' parts to fix a Japanese car? They're about as high for the Honda we had, as for BMWs.

 

[88 4 Fun]

I did considerable research on this when I thought mine was on its way out. The reason they are so expensive is that it is the exact same compressor they use on Porsche and BMW, plus a couple of other High dollar cars

That's nice to know but if this one ever goes out I'll change the whole system out. I'll go to a junk yard, oops I mean auto recycle center and get what I need.