Air conditioning blowing Hot air.

Hi

Went to turn on air now that weathers hot and it only blows hot air. It did work good last summer. It is a 96 bonny with the climate control system. I went and bought a recharge can and tried recharging the system. It doesnt seem like it wants to take the freon and then I noticed the compressor never kicks in. The freon guage reads in the red or low freon. Is there a safety switch that shuts off compressor when it detects low freon.?? How do you recharge the system if the compressor wont kick in??

Any advice surely appreciated .

you'll just have to keep the ac on full blast while engine is running... it should eventually take up the charge from the can

even the guys at an autozone can try to help you, but after ~5minutes and it's still not taking the R134A refrigerant, you have a major leak & will need to go get it professionally done

OK I will try it longer. I only ran it a few mins when I tried it. I read somewhere about running a hot wire to the compressor to get it to run and circulate the freon untill its gets enough into the system to get the compressor to run on its own.

I wouldn't recommend doing that. Your compressor is being saved by that pressure switch. That switch is on the low pressure side so you should be able to get enough R134 in it to get the compressor to run.

Many times, the small cans don't have enough pressure to fully charge the system. You can place the can in a bowl of hot water to help raise the vapor pressure of the refrigerant. Look at the frost line that forms on the can. It will tell you what the level is.

When it does kick in, it will cycle off quite a bit until the charge comes up and stabilizes.

Maybe a stupid question but are you putting the AC on MAX with the fan full blast? This should force the compressor to stay on. Also, ambient temp. can make a difference in whether the compressor comes on or not.

magnet, the low pressure switch will protect the compressor from turning on until there's a minimum pressure achieved... that way there's oil going to it as well as the refrigerant

he can bypass it, but it'll be at a risk of seizing it up when the oil isn't there to lubricate the compressor

Thanks for the input. Yes the air is on with blower full blast. It is not the manual air/heater style but the automatic style of system. Where you set the temp and the system automatically decides if you need heat or air depending on outside temp and the temp you enter . I put in the lowest temp I could assuming that would turn on the air . But tried several temps it didnt turn on compressor.

I am going to work on this again tonite. And try longer this time to see if I can get enough freon in it to activate the compressor. Although I did try for about 5 mins last time.

First things first...

This is a 96 Bonneville, this car uses a Variable stroke compressor... The system does not have a low pressure switch... This system uses a Pressure sensor that is monitored buy the PCM, if the pressure is correct the PCM will command the compressor on when you have selected AC on..

Does the compressor turn on at all?

Do you have the Electronic Climate Control? And if you do does it ever display " --- "?

Ok just caught your last post...

Does the AC system have anything in it at all? And was this a recently problem?

This is my daughters car so dont know exactly when the air quit blowing cold. It did work great last summer. I was assuming it had a slow freon leak.

No the compressor never kicks on. When I tried recharging it last weekend the tube close to where I was injecting the freon did get sweaty and I thought it would eventually get frosty and start blowing cold air . Then I noticed the compressor never kicked in. It is spinning feely and not squealing or anything. I tried several heat settings and fan speeds but compressor never kicked in.

I was in a hurry an didnt have time to continue trying to recharge so we stopped. I hope to work on it again today.

The problem with this type of ventilation system is its all automatic and if the air conditioning function is not working the system keeps blowing air thinking its cold air but its not- its hot air. making it real miserable driving as it keeps dumping hot air into the car. Even if you push off to shut off the whole sytem it keeps blowing some hot air in.

Ok- worked on this car again last nite. Did get the freon recharged. Put in a big bottle. Pressure is around 40 which is about what the bottle says it should be.

The compressor is running and the large tube where I put freon in is cold. Only problem is it still blows only hot air? I checked all the fuses that say Ac and they are OK. Even the ones under the glove compartment. The ac control panel seems to be working ok. The blower comes up to hi speed depending on the temp you enter.

Is there a flapper door somewhere controlled by vacuum in the duct work that diverts the air depending on mode (heat or Ac) that may be stuck??

There is a Temp control Actuator, a lot of the time we see this actuator crack a gear internally and a lot of the time it fails to hot... But, this usually pisses off the ECC( Electronic Climate Control )... The actuator is attached to a rod for the temp door... Its a real PITA to get to...