2nd Gen Non-Engine/Transmission a/c problems

[Mike C]

I need help figuring out my a/c problems. I do know that my a/c clutch is not engaging, I dont hear it cycling on and off or dont hear it engage when you first turn it on. I did try changing the relay and checked fuse under hood . what else should I check? Thanks in advance.

 

[B.G. Smith]

The most likely problem that causes the compressor to not come on is low refrigerant. It won't come on if the presssure is below around 26#. If you don't have access to a set of refrigerant gauges, you can disconnect the wires at the clutch cycling switch located in the side of the accumulator and jump across the two terminals, this should engage the compressor if the engine is running, let it run about a minute or two and then feel the line coming from the evaporator to the accumulator and see if it is cold, if not then you are probably low on refrigerant. Don't let it run too long as the comppressor can pull the internal pressure below atmospheric pretty quick if the charge is gone and air might enter the system through the compressor seal. bg

 

[Mike C]

Thanks BG I will give that a try. Where exactley is the accumulator located? Is there a good set of directions on adding more refrigerant I dont mind getting the proper tools and gauges to do the work but I want to be sure I know how to do it right and can handle doing it right.

 

[B.G. Smith]

The accumulator is located on the passenger side between the air filter box and the engine, it is about 3" in diameter and has a line coming into it from the firewall and a line coming out of it which goes to the suction side of the compressor. It has the clutch cycling switch screwed into one side or the top of it. It either has a low pressure test port in it or there is one in the line going to it. It is a special fitting that can only be accesed with the proper hose/gauge and fitting made for 134-A refrigerant. You can buy just a hose with the fitting for adding refrigerant I believe. The high pressure line also has an access fitting which is a different size to prevent hooking up to it by mistake and blowing up a can of refrigerant in your hand. If you try to add the refrigerant be sure you get the can that has just 134-A as they also sell a can with 2 oz. of oil in it. Too much oil in the system will reduce it's ability to cool. The system full charge is only 32 oz. so don't add too much, the system is much more sensative to overcharge than R-12 used to be and a little too much refrigerant will really slow it down. Good luck. bg

 

[Mike C]

B. G ,I jumped out the pressure switch and the compressor did kick on so I bought a kit from advance auto and when I first hooked up the gauge was near zero. I then started by adding a little at a time and the compressor started kicking on and off. The gauge starts at 45 and when the compressor kicks on it goes close to zero. When it kicks off the gauge will steadly climb back to 45. The compressor kicks on for about two seconds and then off for about 9 seconds and reeats this cycle over and over. Any suggestions now? Thanks in advance.

 

[B.G. Smith]

Sounds like it was completely empty? If it is still not cooling you can add another can, if it's not going out too fast it should start cooling. Be aware that you have a leak somewhere and you may be wasting your money to charge the system without finding/repairing the leak. As stated before, the capacity is 32 oz. The cans hold 14 oz. I believe so two cans will put you near capacity. bg

 

[Mike C]

B. G. ,Thanks for all the help. This site pays off again. What I think was happening was I was checking the pressure while the compressor wasn't engaged and after reading more on the subject I started adding a little more each time and the compressor started staying engaged a little longer each time . I put in a 19 oz can and the compressor stays on and the pressure is about 25-30 and blowing pretty cold air. I am sure there must be a leak now I will have to try and find that. I will keep and eye on pressure to see how fast it is leaking. Thanks again,I appreciate a bunch.

 

[B.G. Smith]

Sounds good. The clutch cycling switch opens at about 25# and cuts back in around 45#, if it's staying on now while idling then you should be close to full chg. Pray for a cool front. bg