AC diagnosis | air blows, it's not cold

[2L8IWON]

Hello all,

My car is a 2005 GT with 32k miles. I use it seldomly; weekends, shows, nice cruises, etc.

Got in it the other day to go somewhere and the air blew but it wasn't cold. Eventually it cooled down, but not to where it used to be.

Without going to a shop, how do I tell what to do to fix it? Is it as easy as filling the R134?

Thanks

Jesse

 

[Fullboogie]

Save yourself some money. Get a manifold/gauge kit from Harbor Freight, learn how to use it, and charge your freon yourself. I've saved myself a ton of money doing this on my own vehicles. For example, you can buy a pound of freon from Wal Mart for $6, while a shop will charge you between $20 and $30 for that same freon - plus labor charge. The manifold/gauge set is $50.

 

[Kylar]

Refilling it wont help if there is a leak, just sayin.

 

[P-51 Performance]

you can also rent the manifold gauges from an autozone , just have to leave a deposit. look up on youtube how recharge your a/c system lol.

 

[utm18]

Go to auto zone, advance auto or other parts store. Get a cheap recharge kit and use it. It may last year's it may last a day. But it's the cheapest way to troubleshoot it your self without paying somebody

 

[2L8IWON]

Thanks guys. I am wondering if I have a leak or if it's a easy fix. I'll go the autozone route.

Thanks again

 

[Dino Dino Bambino]

Thanks guys. I am wondering if I have a leak or if it's a easy fix. I'll go the autozone route.

Your AC system has a small leak so I suggest you have it checked out and dye tested to find the source. Otherwise you'll be wasting money to refill the system only to have the gas leak out again.

 

[Aesthetics28]

Go to auto zone, advance auto or other parts store. Get a cheap recharge kit and use it. It may last year's it may last a day. But it's the cheapest way to troubleshoot it your self without paying somebody

This ^^^

They have ones that stop tiny leaks with it so dont be afraid to pick it up and test it. usualy run around 40$

 

[Marble]

Thanks guys. I am wondering if I have a leak or if it's a easy fix. I'll go the autozone route.

Thanks again

I very very rarely use my AC. Even the defrost in the winter is rarely used. There has been a few times where the air wouldn't get cold, especially when it's 110 out or so. It's always corrected itself. I have no idea why it does it but it's random.

Seems like if it hasn't been used in a while, it takes a bit to work correctly. If I turn it on for just a few minutes every week or so, it works normally.

Follow the advice above and charge it yourself.

 

[joe_momma]

I'm in the same boat - it cools, but not as efficiently as it did last year. I'm going to stop by and grab one of those recharge kits. My car is also an '06GT.

 

[Wild White Pony]

I just did an ac repair on my Grand Cherokee today, I used a can of UV Dye Shot to find the leak.
http://www.jbtoolsales.com/interdyn...e-dispenser/?gclid=CKbqn4mTi8YCFRAyaQodQ3sATQ

You have enough for 5 shots. Note to make this work right you need the AC clutch engaged for both the shot and filling R134. If you lost too much Freon the clutch won't engage cause the low pressure switch will kick it out right away. I took a paper clip and jumped that switch. You can do this on a 2 wire switch but not a 3 wire cause the 3 wire is switch looking for a value within a certain range.

The UV dye also contains oil, this oil is easy to see even without a UV light, it bubbles on hoses and when it drips on something hot it stinks to high heaven and makes a crap load of smoke.

Took about 3 minutes to find the leak in the low pressure hose, easy fix.

 

[kytoploader]

I used to design and test heavy truck and automotive a/c systems including a few Ford's. The Ford style joints leak slowly even when new. With a 9 year old car its possible you could put some refrigerant in and last a couple more years. Alternately, you could put a can in and still have problems. The right way is to use the dye and see if there is a large leak, fix it and then recharge. If it was mine, I would buy or rent the gauges and put some refrigerant in. If it doesn't work you are still only out a few bucks.

 

[86GT351]

Thanks guys. I am wondering if I have a leak or if it's a easy fix. I'll go the autozone route.

Thanks again

AC Systems are High Pressure Sealed Systems. Based on your symptoms it appears you have a small leak and the Freon Level is low. With that said it is not pulling enough humidity out of the cabin and the car does not feel as cool

 

[retfr8flyr]

I had a problem with my A/C a couple of years ago and they couldn't find the leak. They had this brand new huge fancy Snapon A/C machine, which they were still learning how to use and it kept telling them there wasn't a leak. They final found it was the needle valve on the low pressure side that was leaking and that's one of the places where the machine hooked up so it wasn't showing a leak. Drove the shop crazy for 2 days.

 

[joe_momma]

My car ended up taking nearly a full can (12 oz. I think) of freon. It is cooling much better now. I bought a reusable hose kit and a separate can that was just freon with no leak stopper at WM.

 

[Fullboogie]

The fact is, despite being a "closed" system, almost all A/C systems leak a tiny amount over time. It's just the way it is. Buying a manifold/gauge set and recharging your system will pay for itself in one use. In the last two weeks I've recharged my 4Runner, GT500, and my wife's car for a total investment of $50 for the manifold/gauges and $18 for the freon. Saved myself hundreds of dollars. Been doing this for years on all my cars without issue.

 

[MikeVistaBlue06]

Just an FYI, when you load a new tune sometimes the AC doesn't work immediately. It may take it a couple of minutes to kick in.

One thing the OP needs to do is see if the compressor is engaging and spinning. IF the pressure is too low in the system, it will not engage for you to either check it or fill it. You'll have to jumper the low pressure switch on the suction side (bigger hose/pipe) to get the compressor to engage so you can get some r134a into it.

 

[s8v4o]

Another issue could be the radiator/condenser fan. Can you confirm the fan is working? If it's not then the AC would appear to be working better "later" but it may just be because you're driving down the road at a decent speed with enough airflow to cool the condenser. I've had my fan go out due to the fuse panel melting like many others have had.

If the fan is working do as another person already mentioned and get yourself a set of gauges and check the system yourself.

 

[oldVOR]

IF the pressure is too low in the system, it will not engage for you to either check it or fill it. You'll have to jumper the low pressure switch on the suction side (bigger hose/pipe) to get the compressor to engage so you can get some r134a into it.

You don't need the compressor running to fill the system. The pressure in a tank of refrigerant will always be higher than that of the AC system and it will push the refrigerant into the system.

Outside of checking the normal parts; condensing coil is clean with no air obstructions, evaporator coil is clean with no air obstructions, cabin air filter is clean with no obstructions. With these checked, you can move on to system operation.

The best way to ensure a properly operating AC system is to evacuate the refrigerant, place a vacuum pump on the system to draw down (out) any air/moisture (20 minutes for each pound of refrigerant is sufficient), check the system on vacuum with a micron gauge to determine if there are any leaks, if no leaks noted, then fill the system by WEIGHT as per the AC system decal under the hood.

Once complete, run the AC on coldest setting with fan speed on high and check your system pressures. Record the ambient temperature when the system pressures were checked. Now you have the baseline pressures for your system at that ambient temperature with a full charge.

For future reference when checking the system pressures:
Lower ambient temps = lower system pressures
Higher ambient temps = higher system pressures

There are tables to determine amount of system pressure decrease or increase based on ambient temperature differentials.

Low refrigerant levels will show up as lower than normal system pressures at any given ambient temperature.