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where to start with fixing a/c

32K views 31 replies 18 participants last post by  Gearhead65  
#1 ·
My a/c has not worked for a few years on my imp and I was wondering where the first place to start with what is bad. I know there is the compressor ($$$) evaporator, drier, evap.., ect ect but where do i start to figure out exactly what is bad and what needs replaced?
 
#2 ·
Visually check all the connections AC compressor and rubber hoses for signs of leaks (The AC oil will accumlate on the leaking area) AC compressor shaft seals can leak (The clutch will be leak) The big middle O ring in the compressor case can also leak. Check all the connections that are nutted together as they have O rings that can blow out. A really low charge (almost empty) wont allow the AC compressor to turn on. A low charage might allow the AC compressor to cycle, But it will be cyling rapid which is the typical sign of a low AC charge.

No AC usally means a leak, Or wiring problem/ the coil in the AC clutch going bad and not allowing it to engage.
 
#3 ·
unfortunetly your probably gona have to take it to a shop to check it out. first check to see if there is power and ground at the compressor (runninig with ac on). if there is power and ground and the comp doesn't run, then you'll need a clutch. if theres no power the system is probl low or empty. to check for leaks you'll need to charge the system with nitrogen, then spray it down with soapy water to check for bubbles.
sometimes you can find leaks by looking for oil stains on components.

hope that helps

Andre
 
#4 ·
some shops use dye to find leaks. remember to change your orfice and condenser for warranty purposes. so far i would save up or in other words spend more money for an AC delco compressor. had to do mine bout 5 yrs ago. i live in florida, hot and humid weather. and havent had an issue, other than pressure service every summer.
 
#5 ·
I think you mean orifrice and RECIVER DRYER.
 
#7 ·
The first thing to do is check and see if you have any refrigerant in the system. Do so by hooking up a manifold gauge set to the A/C system. If you do, try turning on the A/C and see if the compressor runs. If it doesn't run, you may have to put a jumper in the pigtail for the low pressure cycling switch, located on the accumulator/dryer. If the compressor won't run, sounds terrible, or is locked up, then you need another compressor. If your system has no pressure, then you have to track down the leak.

If you're not sure where to start, you should honestly start by reading this: http://www.aa1car.com/library/ac98.htm
 
#8 ·
To save yourself some time and trouble take it to repair shop that does a/c work. Tell them your a/c does not work & you are looking to get it working again. This is your best way to go.
Now since I do this kind of work for a living & came into my shop with this problem this is how I would tackle it.
1.) Perfrom visual inspection to make sure compressor & all components look good. Check for any freon in system. If system is empty I would remove & inspect the "orifice tube" & replace it if all is good. This is a cheap part.
2.) Manually jump the low-side switch to see if compressor engages & clutch is not bad.
3.) Pull system into a vaccuum for at least 30 minutes or more & see if the system will hold hold the vaccuum for at least 20 minutes.
4.) If all checks out I would recommend the replacement of the "reciever-drier". I would replace it. Add about 4.0 oz of recommended oil. There is a reason for the 4 not just 1 or or 2. Pull system back into a vacuum & hold for at least 15 minutes.
5.) Charge the system & check operation.

Just an idea of what might be done.
Any questions????
 
#10 ·
2.) Manually jump the low-side switch to see if compressor engages & clutch is not bad

So I have read this several times in different topics and still have no clue what you guys are referring too.If anybody have a picture of it and can tell me exactly what and how you jump it,I would be very thankful.
 
#11 ·
Image


Turn the car on. Put the AC on MAX. Unplug that connector that has the green wire in the pic above. Take a short section of wire, and connect the two terminals inside that connector you just unplugged. Watch the compressor, it should start immediately. DO NOT let it run for more than a few seconds. If it does run, you are ready to test for leaks. If it doesn't run, you have other problems than low pressure in the system.
 
#13 ·
Maybe. Now you need to get a gauge on it to see what the pressure is. If low, you need to add r134a to bring the pressure up. When high enough, the compressor will cycle, UNLESS the pressure switch (the part that the connector attaches to) is defective.
 
#17 ·
Can the pressure switch on the accumulator be replaced without depleting the charge? I know theres a scrader valve behind the switch not sure if its built into the switch or not.
 
#22 ·
+100, I wrapped both hoses, but actually only the line you see covered in the read heater jose needs to be done, as it has a tendency to rub on the upper CTRL arm, thruough the suspension's jounce & rebound actions.

Image


As far as diagnosing the problem you are experiencing, if you don't have the tools (Gauges, Sniffer) you're wasting your time.

I'd suggest taking it to a shop, and have them do the root cause analysis on where the problem lies.

Check out post #7 & 13 in the sticky here:

http://www.impalassforum.com/vBulletin/showthread.php?t=244168

Print out the picture in post #7 and reference it while servicing the system.
 
#21 ·
My a/c has not worked for a few years on my imp and I was wondering where the first place to start with what is bad. I know there is the compressor ($$$) evaporator, drier, evap.., ect ect but where do i start to figure out exactly what is bad and what needs replaced?
You might not like this idea, but you should really take it to a professional and let them test a vacuum to make sure it doesn’t have any leaks. They can then append the proper amount of refrigerant and oil. In a long run, you will found out that this idea make you saved more money. The vehicle should diagnose using some gauge, so it is very risky to just try those kits available in some shops.cwm8
 
#24 ·
Hells to the yeah!! I'm writing from my smartphone now (away from the house) but I'll go into great detail as to what you need to do. I had a similar prob on my 9c1. The compressor seized and started smoking the serpentine belt before I could shut her down.

Been there-done that similar service.

I'll be home in approximately 3 hours with FULL details on what to do and replace.
 
#31 ·
I'm currently repairing my AC system since the compressor froze. I just went ahead and bought the gauges and the 3 CFM vacuum pump from HF since it wasn't much more than an AC shop was going to charge. The AC shop was going to charge $120 just to vacuum the system. Today I flushed everything and everything seemed to come out pretty clean. My only concern is that the evaporator has puddled Acetone since what I put it in didn't seem to ALL come out :/ So, I left that line open and hopefully it all evaporates out by the time I put my new compressor in (tomorrow, hopefully). I'd rather be doing this instead of a shop anyway since now I am learning how to do this myself. I'd much rather do my own work.
 
#32 ·
Also, check around for a Haynes Air Conditioning book. Has a lot of good info.