A/C not cold, quick question...

[Gambaholic]

Ok so my A/C has been blowing cool (not really cold mind you) more or less since I bought my Jeep (97 4.0 TJ) a few months ago. It usually starts cool then will get a little colder after a few minutes and be alright.

The last week or so it has also started loosing the cool air altogether and just blowing that glorious Arizona July heat right in my hairy face.

I verified the compressor clutch is engaging (A/C on full, recirculate on, clutch is spinning). I bought a can of A/C Pro thinking the refrigerant would be low (which would indicate a leak but I was hoping a small one the A/C Pro would bandaid and get me thru the summer.)

Okay so per the instructions on the can I put the test gauge on the low pressure port to check the pressure before recharging and the gauge reads in the green indicating no charge needed.

So my question(s) is, does this mean there is no leak? The compressor clutch is working so is there something else that it would most likely be?

I’m guessing it’s time to pay a pro but i don’t want to if there is something else I can/should check first.

The Arizona desert in summer is a less than pleasant place to be without A/C!

 

[ohiopatriot]

With r134 you can't go by pressures. The only way to correctly charge is to measure/ weigh the amount being installed after evacuation. A couple ounces or so to much or to little it won't work right. R12 was much more forgiving and could be done by pressure. The gauge on the can you bought just means the system is not empty. Most things you can DIY, but this I'd recommend a shop for, Arizona should have many reputable AC specialists.

 

[Boinked]

You might want to go down to autozone or o'rileys and rent (free) a set of gauges and check it. Cant trust the can in Arizona to hot. Link to what you should see at a given temperature. http://rechargeac.com/how-to/ac-system-pressure-chart


Late edit.... might want to just refresh the r134a. I want to say it only 20 or 22 oz of 134a. (I cant remember) O'rileys has cans for 10 bucks. 12oz you can get the gauges and vacuum loaners. About a 2 hour job.

 

[Alex01]

You might want to go down to autozone or o'rileys and rent (free) a set of gauges and check it. Cant trust the can in Arizona to hot. Link to what you should see at a given temperature. http://rechargeac.com/how-to/ac-system-pressure-chart


Late edit.... might want to just refresh the r134a. I want to say it only 20 or 22 oz of 134a. (I cant remember) O'rileys has cans for 10 bucks. 12oz you can get the gauges and vacuum loaners. About a 2 hour job.

x2 I changed the a/c system on my mother in-laws chevy and rented the kit from autozone. Used it on the tj as well to refresh the system.

Make sure you also "rent" the vacuum pump because you need to pull all the air out of the system before adding new freon.

 

[Gambaholic]

Just a follow up for anyone this might help in the future. The problem turned out to be faulty wiring.

From the repair notes:
“Monitored data PIDS while driving and found the AC compressor command being disabled intermittently while driving. Further testing found a random break in the wire leading to the high pressure switch causing loss of communication....”

A little back story... Before they found the problem they did a normal AC service. Evacuated the system, pressure tested for leaks, refilled the system, and added dye to make it easier to find future leaks. My AC was working better in the sense that when it was blowing cold it was colder than before but it was still fluctuating temperature so I took it back to the shop. After a few hours they called me back and told me they found the problem! :aaaaa: They said the break in the wire was internal meaning there was no obvious signs outside the wire casing that would indicate damage. I would have never found this on my own. I would have started replacing parts one by one until it worked properly. In this case I could have replaced the entire system part by part and still not have fixed the problem!

 

[Matt77]

I was going to say ( I know you fixed it already ) but sometimes when you add anti freeze you get air in the line. If you open the radiator cap turn the car on, with heater on and full blast that will purge the air. Thus making air blow cold again. This might help someone else.

 

[Gambaholic]

I was going to say ( I know you fixed it already ) but sometimes when you add anti freeze you get air in the line. If you open the radiator cap turn the car on, with heater on and full blast that will purge the air. Thus making air blow cold again. This might help someone else.

Does this still work if you have done a heater core bypass?

 

[Matt77]

Does this still work if you have done a heater core bypass?

I'm not sure. But I researched that trick when my car was overheating. I added antifreeze to the radiator and the overflow. But after I did that the ac stopped blowing cold. And to fix that you open the radiator cap turn the car on with heater on full blast. When you you look at the radiator hole with cap off, you will see bubbles coming up and gently squeeze the upper and lower radiator hoses to caress air out. At first when your heater is on it won't blow hot but as you purge the air out of the system the heat will get hot and your ac will get cold again. This is only if air in your system is trapped.

 

[ohiopatriot]

Does this still work if you have done a heater core bypass?

No. I'm not sure what he's trying to tell you, but purging air trapped in the heater core will not affect your AC cooling, unless it is so low on coolant the engine is overheating, but then your not purging air, your refilling the system. Having your core bypassed isn't a problem for it either. It is important to get all the air out of the cooling system to most efficiently cool the engine and have the best heat possible though.

Glad you found a shop who was able to get you fixed up. Sounds like they had a sharp tech to find that issue.

 

[Matt77]

No. I'm not sure what he's trying to tell you, but purging air trapped in the heater core will not affect your AC cooling, unless it is so low on coolant the engine is overheating, but then your not purging air, your refilling the system. Having your core bypassed isn't a problem for it either. It is important to get all the air out of the cooling system to most efficiently cool the engine and have the best heat possible though.

Glad you found a shop who was able to get you fixed up. Sounds like they had a sharp tech to find that issue.

 

[ohiopatriot]

So you had no new information to share and you be a dick for nothing? For me trying to help. Your a class act pale.

Sorry to offend snowflake, but I added factual information. What you said was nonsensical and confusing. :nusenuse:

BTW, I'm ok with being a dick, but don't call me pale, pal.

 

[Matt77]

Sorry to offend snowflake, but I added factual information. What you said was nonsensical and confusing.

 

[ohiopatriot]

It's going to be OK, this site has a "safe place" for guys like you.

Click on my avatar and click "ignore". Pale guy goes away.

Thanks for your service btw.

 

[4.0_daniel_]

I was going to say ( I know you fixed it already ) but sometimes when you add anti freeze you get air in the line. If you open the radiator cap turn the car on, with heater on and full blast that will purge the air. Thus making air blow cold again. This might help someone else.

I know im 5 years late but how long should i leave it on like that for?