AC compressor not running
Thread Starter
Heel & Toe
Joined: Dec 2012
Posts: 15
Likes: 1
From: Philly
AC compressor not running
Hello fellow corvette owners, I purchased my first corvette about a year ago (1998 coupe). Over the past year I have been doing some work (brake upgrades and so on) now I 've come to the air conditioning and I need some help. Here's what happens: turn it on light blinks compressor does not start, where do I start? Any help will be greatly appreciated, thanks in advance!!!
Team Owner
Joined: May 2006
Posts: 21,473
Likes: 356
From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
To me it sounds like the Freon pressure is Low and if it is then the Low Pressure switch is not allowing it to come on and cycle -
You will need to have the pressure checked -
You can also look for any blown fuses - (under the hood and passenger footwell area)
As stated check for the HVAC Codes in the DIC
I just check my pressure for you with the Vette "OFF" so you will know what the pressure should be at when you hook up a gauge on the Low and High Side (Should be equal pressures:
Pressure is at 100 PSI (If it is not at that or real low then you need it to be charged and at least find out where the leak is coming from)
I have found that the shrader valve (Fill valve, suction side, Low side) is usually the culprit and it leaks and bleeds off the pressure slowly!!!
I gotta jam now! Keep us posted!
Thanks,Matt
You will need to have the pressure checked -
You can also look for any blown fuses - (under the hood and passenger footwell area)
As stated check for the HVAC Codes in the DIC
I just check my pressure for you with the Vette "OFF" so you will know what the pressure should be at when you hook up a gauge on the Low and High Side (Should be equal pressures:
Pressure is at 100 PSI (If it is not at that or real low then you need it to be charged and at least find out where the leak is coming from)
I have found that the shrader valve (Fill valve, suction side, Low side) is usually the culprit and it leaks and bleeds off the pressure slowly!!!
I gotta jam now! Keep us posted!
Thanks,Matt
Thread Starter
Heel & Toe
Joined: Dec 2012
Posts: 15
Likes: 1
From: Philly
Picked up a set of gauges at Harbor Freight for $50 bucks (not bad), hooked them up and only had about 12 pounds on each side. AutoZone having a sale on 134a. Low side valve not much dirt around, like I said the ac hasn't worked since I got the car last year and who knows how long it hasn't worked but it will be working soon!!! Thanks for the replies and I'll post any changes.
Team Owner
Joined: May 2006
Posts: 21,473
Likes: 356
From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
Picked up a set of gauges at Harbor Freight for $50 bucks (not bad), hooked them up and only had about 12 pounds on each side. AutoZone having a sale on 134a. Low side valve not much dirt around, like I said the ac hasn't worked since I got the car last year and who knows how long it hasn't worked but it will be working soon!!! Thanks for the replies and I'll post any changes.
You will need to jump the low Pressure switch in order for the Compressor to turn on - you will be able to put some in the line with a can "BUT".....
The best course of action before you do that and waste time and money and the possibility of destroying parts, you also should get an AC evac pump and pull the rest of the freon out and see if it hold vacuum -
If it holds vacuum then the o-rings are good "IF" it does not then you need to replace the o-rings (you can get a kit at any local shop) -
The if the vacuum holds (because you cannot have any air in the lines) you hook up you freon and allow the vacuum to pull it in and charge as much as possible -
We can go on from here once you have the above answers!
Thanks,Matt
Team Owner
Joined: May 2006
Posts: 21,473
Likes: 356
From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
You can also get the little A/C Evac pump at harbor Freight for the cheap!
I made one out of an old refrigerator pump - works super awesome!
Thanks,Matt
I made one out of an old refrigerator pump - works super awesome!
Thanks,Matt
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
Melting Slicks
Joined: Jul 2006
Posts: 2,332
Likes: 31
From: Silver Spring MD
Did the same 30 years ago - still pulls 30 inches of vacuum
Sounds like low R134a. Can get a case (12 cans) at Sams or Costco for the price af 3 or 4 cans at AZ or Advance. Buy a case and you will have a good stock. Just need a can piercing tool available for about $5 that will screw onto the center charging hose on your gauges.
Thread Starter
Heel & Toe
Joined: Dec 2012
Posts: 15
Likes: 1
From: Philly
No HVAC codes in the system. I put a vacuum on it for 45 minutes (close to 30 in.) and shut off the pump, needle barely moved in 2 hours. So I would think there is no leak. Now that I think about when I first started this project the low side Schrader valve cap was not secured properly, it was sort of just pushed on not screwed. Well thanks again for the posts, I guess the next thing to do is charge it up.
Melting Slicks
Joined: Oct 2007
Posts: 2,798
Likes: 8
From: It's true money can't buy happiness, but it is more comfortable crying in a Corvette than on a bicyc
St. Jude Donor '13
Big Lots had freon for $6.77 normal price is still only $8.
I wonder what the EPA would think about the advice that you just get a vacuum pump and pump the freon out? Last I heard its a possible $25,000. fine for releasing freon to the atmosphere. Proper way is to use a recovery machine, which is cost prohibitive. I'm just saying it's the law and not a good idea to post potentially criminal advice in a public forum.
I wonder what the EPA would think about the advice that you just get a vacuum pump and pump the freon out? Last I heard its a possible $25,000. fine for releasing freon to the atmosphere. Proper way is to use a recovery machine, which is cost prohibitive. I'm just saying it's the law and not a good idea to post potentially criminal advice in a public forum.
Burning Brakes
Joined: Jan 2011
Posts: 1,067
Likes: 46
From: Springfield IL.
Oldtimer
If you hook up a vacuum pump up to a system with any pressure it'll blow the oil out of the pump. When charging your system, make sure you know what the outdoor temp is and go buy the head pressure. The temp scale is the blue numbers on the manifold set. Don't over charge or you will ruin your compressor. R134a is an ozone friendly refrigerant or you couldn't just buy it without a refrigerant license.
Melting Slicks
Joined: Jul 2006
Posts: 2,332
Likes: 31
From: Silver Spring MD
Vacuum pumps EVACUATE any AIR in the system they do NOT PUMP REFRIGERANT OUT
Big Lots had freon for $6.77 normal price is still only $8.
I wonder what the EPA would think about the advice that you just get a vacuum pump and pump the freon out? Last I heard its a possible $25,000. fine for releasing freon to the atmosphere. Proper way is to use a recovery machine, which is cost prohibitive. I'm just saying it's the law and not a good idea to post potentially criminal advice in a public forum.
I wonder what the EPA would think about the advice that you just get a vacuum pump and pump the freon out? Last I heard its a possible $25,000. fine for releasing freon to the atmosphere. Proper way is to use a recovery machine, which is cost prohibitive. I'm just saying it's the law and not a good idea to post potentially criminal advice in a public forum.
