'99 LeSabre - AC Not Working

1999 Buick Lesabre Custom 125K miles. Yesterday got in my car and went to lunch, AC was on and working, blowing cold air. 30 minutes later got back in my car, started it up, pushed "Max" AC button on, but now it is not blowing cold air. It's blowing only outside air as if I had the "Vent" button on. Lifted hood and noticed that the AC clutch on compressor was not engaged. I tried the "Defrost" button, but still compressor clutch did not engage. Also, when "Max" or "Defrost" button was on and I was looking under hood and noticing no AC clutch engagement, the two cooling fans were NOT on. I thought that when you turn on AC, the cooling fans would turn on, but maybe this is only if the compressor is running? I'm leaning towards a relay or blown fuse, but do not have the shop manuals or Haynes book to find out where the fuses or relays are located for the AC system. Can someone tell me where the fuses or relays for the AC system are? Also if it does not turn out to be a fuse or relay, any other ideas what might be the culprit? Doing some research, I know my car has an A/C clutch diode (not sure what that does, where it's located or how to test it). If this was not working properly, would it prevent the AC clutch from engaging? Thanks.

Number one cause of mobile A/C failures is loss of refrigerant due to a leak-

Put a set of gages on it- if less than 47 psi- the a/c compressor will NOT run- to save the compressor from burning up from lack of lubrication--

Then if yours is low- the most common leak location is the compressor shaft seal- followed by the compressor case seals-- is your clutch /pulley slinging oil? Is the compressor body oily?

Post back and we can go from there.......

Automatic a/c
http://i83.photobucket.com/albums/j293/airjer/AF%20Stuff/leasbreauto1.jpg
http://i83.photobucket.com/albums/j293/airjer/AF%20Stuff/leasbreauto2.jpg

Manual A/C
http://i83.photobucket.com/albums/j293/airjer/AF%20Stuff/leasbremanual.jpg

The first thing I like to do is put a set of gauges ion it. It is entirely possible it is to low on REFRIGERANT. (just in case my new friend reeker happens to read this)

It has the manual A/C controls.

Clutch Pulley is not slinging oil. The compressor body is not oily. I did not see any oil coming from compressor. I'll look into your suggestion that it might be a refrigerant leak after I check fuses and relays associated with the A/C clutch once I find location. Thanks for the input.

In the scheme of mobile a/c failures- relay and fuse failures happen about 3% of the time--65% of the time it is low on refrigerant--

Although the Lesabres were known to have clutch coil shorting out problems from anti-freeze dripping on the compressor from water pump leaks.

Have you had water pump leakage?

Fuse for compressor is red 10 amp in underhood fuse block.

Last week my air went out, just like u describe. We put 1 big and 1 small can of 134a and it clicked right on and worked since.
Chris.

You guys were right. I got a hold of a recharge R-134a kit with gauge. Started filling low side port and compressor kicked in. This saved me some money. Thanks for all your help. :smile:

That depends on how long it lasts :) . IMO if you have to recharge once a year its not so bad, if its every other month its time to fix it.

I too have this AC issue and determined its a leakl but the dealer cant find it... apparently.. I've had it recharged twice and it lasts me almost the summer.. I noticed that it only really leaks when I have it running... they put some dye or something in last time and still not able to determine the location of the leak... im a diy er ... pretty handy but can someone walk me through exacly where to check and for what.. also can I guage this myself. Is it easy for me to recharge myself if needed and where do "I get the R134A kit..
I live in Vancouver BC- west coast
thnks

Any auto parts dealer should have a recharge kit & most include instructions. Small leaks such as yours can be difficult to find, better to just add some when needed.

A good way to find your leak is to buy a "sniffer" off ebay and set it to high sensitivity to start (back off if it finds apparent leaks everywhere.) Then probe near the manifold to compressor connection with the AC running on full. Then check the compressor pulley area, then all joints in the tubing, then the condenser, then the accumulator connections, then the connections to the evaporator. Lastly if you still cannot find a leak you may have a leak on your evaporator. If so, the only way to really check is to dig it out which is a major pain in the butt.

If you find leaks lower the sensitivity a notch or two and recheck. When you have it on low sensitivity and it still finds leaks, you've found your major leak source(s).

Note that some leaks simply refuse to be found and perhaps are intermittent or very slow or pressure or temperature sensitive (just guessing really.) This page tells what kind of sniffer to get:

http://www.aircondition.com/tech/questions/30/

so... me again.. we here in BC - Canada are in a heat wave and my old buick lesabre AC has fully crapped out again... Teh goodyear shop will recharge it for 200 plus tax and they said they could throw in a sealer of some sort but in all liklihood that wouldnt work... So, I'm lookinga t another 250.00 or so... I told the mechanic the story and he seems to think my small leak is in the evaporator... even if it were hose or line or compressor .. its all big bucks- they were tossing around numbers 1-2K!!.. Im thinking my car isnt worth much more that 3K on paper ..but heck its in great shape and low KMs... I need the AC... I dont think I can pruchase a recharge kit in my area due to regs... but not sure...I'm open to suggestions from anyone.. thanks
G

so... me again.. we here in BC - Canada are in a heat wave and my old buick lesabre AC has fully crapped out again... Teh goodyear shop will recharge it for 200 plus tax and they said they could throw in a sealer of some sort but in all liklihood that wouldnt work... So, I'm lookinga t another 250.00 or so... I told the mechanic the story and he seems to think my small leak is in the evaporator... even if it were hose or line or compressor .. its all big bucks- they were tossing around numbers 1-2K!!.. Im thinking my car isnt worth much more that 3K on paper ..but heck its in great shape and low KMs... I need the AC... I dont think I can pruchase a recharge kit in my area due to regs... but not sure...I'm open to suggestions from anyone.. thanks
G

You have five choices:

1. Don't fix it.
2. Pay to properly fix the whole system ($$$$)
3. Pay to have it recharged (HUGE waste of money as it won't last)
4. Get a recharge hose and some cans and charge it yourself ($40-60 US)
5. Buy or rent the tools/parts you need to fix it right. One, a vacuum pump ($200 or so used.) Two, a set of manifold gauges ($50-$100). Three, a digital scale for refrigerant (ebay.) Four, a thirty pound tank of r134a (a big supply but worth it if you do this work all the time--or sell it after using it once and give precise measurement as to what is in it)($80-$120.) Five, a new accumulator and compressor (likely) ($200 total at O'Reilly.) Six, a new orifice tube. Seven, a flush system (optional.) If you don't flush at least use compressed air to blow out debris and old oil, etc. Better yet, use compressed air with a sprayer gun and use Acetone or similar to flush holding the tip of the sprayer flush with a tube opening and have the other end tubed to a tank (an oversize piece of hose over the other opening will work.) You also still need to find your leak. Best to put a little refrigerant in before taking the system apart and find the leak with a sniffer or soapy water (you have to have enough refrigerant to cause the clutch to engage.) If it is on the evaporator, you likely won't find it because it is buried in the dash/engine compartment. To get it out is a big pain. However, if your leak IS there you HAVE to fix it to have AC in this car.

if you see oil looking stuff on your air hoses there is a leak.