2nd Gen Non-Engine/Transmission Air Conditioner Trouble shooting

[Cliffman]

Can someone post the standard step-by-step trouble shooting proceedure. My AC is blowing semi-cold air.



Thanks!

 

[Cliffman]

WOW! no bites ahhh...

 

[Bob4x4]

First you need a set of gauges otherwise you are just spinning your wheels

 

[Allnew2Me]

You don't need AC Cliff, Pahrump is cool this time of year!

 

[Cliffman]

Good Greif, Bout time someone chimmed in here! No heat either Dave so I guess I'm really screwed! Bob, got a cheapo gauge from the local parts store, it came with 18oz of 134. Popped the gauge on the low end, cranked'r up, got up to full operating temp, put the AC on full blast. The compressor kick in and the gauge went to 0. Added the 18 oz. Got cold air but pressure was still dropping well below 25 PSI. Added another 12 oz. That helped but it still drops below 25 psi and kicks off. The system holds 32 oz and I"m up to 30 in. Not sure why the pressure is still dropping below 25 and kicking off the compressor. It's now cycling 4 times per minute which is way better than when I started.

 

[Cosmo]

Find your leak.

 

[Cliffman]

No need to use profanity! ;-)

 

[mweiman]

You say the compressor is kicking in and out 4 times a minute? Was it doing this before you added the second can and how does it cool now. Does it kick in and out faster with the engine revved up? It almost sounds overcharged but that is hard to tell without a high side guage.

Matt

 

[Cliffman]

You say the compressor is kicking in and out 4 times a minute? Was it doing this before you added the second can and how does it cool now. Does it kick in and out faster with the engine revved up? It almost sounds overcharged but that is hard to tell without a high side guage.

Matt

At first it was going on and off every 5-7 seconds. After the first can it slowed down quite a bit but I didn't time it. The air is blowing nice and cold now. The repair manual says to put a temp gauge in the top center vent and measure the temp and compare it to the outside ambient temp. Outside temp was 65 and the truck was blowing 38-40 which was within specs according to the repair manual.

 

[Cliffman]

Just to be clear, it's way better than when I started. I have very cold air again and it's not cycling near as much as it was. My only concern is that it's still cycling and I may have over filled it. I'm not an AC tech and I don't know if this is normal or not. I know the ambient temp has a lot to do this it but again, I'm unsure as to how much and how it should act given all the variables. Thanks for all your help...

 

[Bill Stockard]

Just to be clear, it's way better than when I started. I have very cold air again and it's not cycling near as much as it was. My only concern is that it's still cycling and I may have over filled it. I'm not an AC tech and I don't know if this is normal or not. I know the ambient temp has a lot to do this it but again, I'm unsure as to how much and how it should act given all the variables. Thanks for all your help...

As Bob4x4 posted, without a set of gauges and not monitoring both the low side and high side pressure, it will be difficult to effectively diagnose problems with the system.



Bill

 

[Cliffman]

So what kind of #'s should I be looking for on the high end?

 

[mwilson]

If the outside air was only 65 degrees I don't think that the compressor is going to stay engaged much longer than what you are seeing.



Did you have it on max a/c with blower on high speed???



But as all say above, see if you can bum a set of gauges to check the high side pressure.



Mike.

 

[JMetzger]

65 outside air could be why you have the low side pressure.

 

[mwilson]

Here are a couple of videos to help you...



First one shows the temp to pressure chart at about the 4. 30 minute mark.



Checking Automotive A/C Pressures (updated) - YouTube



This one shows filling with cans using a gauge set. .



Part 2. How to properly charge an auto AC R134a refrigerant air conditioning system. - YouTube



This should get you on the right track... .



Mike.

 

[Cliffman]

If the outside air was only 65 degrees I don't think that the compressor is going to stay engaged much longer than what you are seeing.



Did you have it on max a/c with blower on high speed???



But as all say above, see if you can bum a set of gauges to check the high side pressure.



Mike.

Yes, I had it on Max AC with the blower on high.

 

[Cliffman]

Here are a couple of videos to help you...



First one shows the temp to pressure chart at about the 4. 30 minute mark.



Checking Automotive A/C Pressures (updated) - YouTube



This one shows filling with cans using a gauge set. .



Part 2. How to properly charge an auto AC R134a refrigerant air conditioning system. - YouTube



This should get you on the right track... .



Mike.

That helps alolt. Thanks! This is what I did and it seemed to work good. Arctic Freeze how to video - YouTube



I'm now pretty sure the reason for the low pressure on the low side was due to the ambient temp at 60 degrees. Supposed to be in the 70's today so I'll check it again just to see if the pressure is higher on the low side with a higher ambient temp.

 

[Bob4x4]

The high side pressure is readable with the scan tooll

 

[Cliffman]

The high side pressure is readable with the scan tooll

No kidding! I have a OBD scanner that tells me fault codes but never new I could read the AC pressure with it.