: My AC is blowing warm air



Ralph
05-14-03, 02:47 AM
:( I guess I need new freon in the AC system. Or a recharge, I know that since 1995 the ozone friendly 134-a had to be put in new cars. Obviously my '91 has CFC-12. What will be involved? Can they just change the freon, or do they have to change the compressor, etc? My Chilton repair book recomends that all cars with AC be maintained, and to do that it is good to run the AC for 5 or 10 minutes each month to keep the seals from leaking no matter what the season. My dad never did this and it blows warm. I did follow this guideline for my previous old car for years and it still blew cold. Later this week I will get a price quote from Midas, etc. Does anyone have experience with this??:confused:

Mad'lac
05-14-03, 04:01 AM
I know that they change the o-rings and seals and the oil. Not sure what else is involved but it can be costly.

Katshot
05-14-03, 08:46 AM
All you need to do is take out the "winter" freon, and put in the "summer" freon ;)

Actually Ralph, the "DEFROST" mode turns on the compressor for you and thereby keeps the refrigerant system properly maintained, so you needn't worry about turning on the A/C over the winter.

As for switching to R134a, generally it's just a matter of flushing the system, changing the drier, installing the new service ports, and finally installing the new oil and refrig.

Elvis
05-14-03, 10:19 AM
Canucks don't need AC. Roll down the windows! ;)

Ralph
05-15-03, 12:55 AM
Originally posted by Elvis
Canucks don't need AC. Roll down the windows! ;)

Hey, we were already 80 F yesterday Elvis! My winter igloo melted last month!LOL:D

Ralph
05-15-03, 01:12 AM
Thanks for the defrost info Kat, but that must be the problem, my dad never winter drove it to use the defrost!

AKPsiMC03
05-15-03, 01:52 AM
and R-12 system which is converted to R-134a will not cool as well as a straight R-12 or R-134a system. The R-134a needs a bigger compressor and more pressure to cool. the old R-12 will not cool that well, so at best, a converted system will give you OK airconditionig and nothing more.

Katshot
05-15-03, 09:12 AM
Actually, it doesn't need a bigger compressor. It needs a bigger evaporator and condensor because the R-134a doesn't suck up as much heat as the R-12 and it transfers more slowly.

BeelzeBob
05-15-03, 09:46 AM
I thought switching was going to be a big deal but it wasn't. The new system cooled fine. I didn't even notice a difference...

Katshot
05-15-03, 11:16 AM
Vent temps tend to be "slightly" higher after the retro-fit but usually the system is able to still cool sufficiently.

Ralph
05-20-03, 03:04 AM
Originally posted by Katshot
Vent temps tend to be "slightly" higher after the retro-fit but usually the system is able to still cool sufficiently.

Midas wants 325.00 while the Caddy dealership wants 400.00. Why would the vent fan blow warmer, it is just outside air? And why isn't the new freon as cold as the old stuff? Does this mean that all new cars don't have really cold AC????:confused:

kcnewell
05-20-03, 03:09 AM
Originally posted by Ralph
Midas wants 325.00 while the Caddy dealership wants 400.00. Why would the vent fan blow warmer, it is just outside air? And why isn't the new freon as cold as the old stuff? Does this mean that all new cars don't have really cold AC????:confused:

Ralph, Don't get yer panties in a bunch here! I had my car converted to R-134 two years ago, It'll freeze your ass of when it's 100 degrees out.....Works great!:D

Ralph
05-20-03, 03:15 AM
Originally posted by kcnewell
Ralph, Don't get yer panties in a bunch here! I had my car converted to R-134 two years ago, It'll freeze your ass of when it's 100 degrees out.....Works great!:D

Thanks, that's all I wanted to know!! PS, how did you know I wear panties.....LOL:)

kcnewell
05-20-03, 03:19 AM
It's written all over your face! LOL!

Katshot
05-20-03, 09:04 AM
Ralph,
By "vent temps", I meant A/C output temps (measured at the vents). The Retrofit cars tend to be slightly less efficient and they end up with slightly higher vent temps.

Newer cars (cars that came from factory with R-134a), Have been designed to work with the newer refrigerant and therefore have larger components where necessary to provide the same low vent temps that the older R-12 cars did. It's just when you use the R-134a in the older (smaller) R-12 systems that you will get the slightly lower performance.

Mad'lac
05-20-03, 10:01 AM
You live in Canada!!!! What the hell do you need A/C for?!?!?!?!?
Be happy that the heater works.

Ralph
05-21-03, 12:39 AM
Originally posted by Mad'lac
You live in Canada!!!! What the hell do you need A/C for?!?!?!?!?
Be happy that the heater works.

I'm not sayin' anything bad to that dude, I just saw "Texas chainsaw Massacre!!":D ;) :eek:

Ralph
05-21-03, 04:11 AM
OK, today I noticed that the service AC or whatever light stays on longer after startup and longer than all the other lights. I guess it knows it is time for a change.

Ralph
05-22-03, 02:29 AM
Originally posted by Katshot
Actually, it doesn't need a bigger compressor. It needs a bigger evaporator and condensor because the R-134a doesn't suck up as much heat as the R-12 and it transfers more slowly.

Turns out you are right on the mark. Midas said I could go with a bigger condenser if I wanted it to be colder, but I won't bother. They said as long as the RPM's are up, like on the highway, it will be cold. I don't use it in the city. Oh, yeah, seals, oil and freon as well, of course.:)

Ralph
06-15-03, 01:53 AM
OK, now I am really confused! today we had a fairly hot day (88 F) and assuming my AC did not work, because it wouldn't last month, my better-half said "turn on the damn AC" Knowing NOT to argue anymore, I did! IT WORKED!! Why did it work now and not before? Could it have something to do with the sensor on the dash, because maybe last month it was not as hot? Why would the car not let me manually use AC, or is it under total control of the computer? I am very confused, but with these cars I am getting used to it. I put it on AUTO, then to 18C, the second lowest setting and presdo, ice cold air!? I thought if you wanted cold AC, you put it to the lowest setting which in celcius is 16C. I do understand the workings of a thermostat, but what gives? Oh well, at least I just saved 325 dollars at Midas NOT getting it fixed!

elwesso
06-15-03, 04:56 PM
Sometimes it may take a while for it to kick in and get cold, especially if you havent used it in a while.....

I have a feeling the ambeint temperature sensor is bad, since it works fine on hot days but not on colder days........ Either that, or the AC doesnt kick in if the outside temperature is the same as the temp you set it at!

Im not sure I understand fully what is going on...... Maybe you need to re-think your statement so it makes sense to everyone else......

Let me se if I understand..... It only blows cold air on 18c, not on 16c.....

You may want to check for codes to see if any of the sensors are fishy!

Ralph
06-16-03, 12:25 AM
Originally posted by elwesso
Sometimes it may take a while for it to kick in and get cold, especially if you havent used it in a while.....

I have a feeling the ambeint temperature sensor is bad, since it works fine on hot days but not on colder days........ Either that, or the AC doesnt kick in if the outside temperature is the same as the temp you set it at!

Im not sure I understand fully what is going on...... Maybe you need to re-think your statement so it makes sense to everyone else......

Let me se if I understand..... It only blows cold air on 18c, not on 16c.....

You may want to check for codes to see if any of the sensors are fishy!

No, it also works on 16 (the lowest) Dude. What is the ambiant temp sensor? How many sensors are there, are you referring to whats on the dash?

Maximln
06-17-03, 06:57 PM
No, it also works on 16 (the lowest) Dude. What is the ambiant temp sensor? How many sensors are there, are you referring to whats on the dash?

Ralph--Your thermostat in your car works basically like the thermostat in your home. When you adjust the temperature in your home on a hot day to 72 F, the system comes on, cools your home until the temperature at the thermostat reaches 72 F, and then turns off. When it warms up again, the system will come on again, cool it to 72 F and then shut off again. By moving your home thermostat to say 65 F, 60 F, 55 F, etc., the discharge air doesn't come out any colder that it would at 75 F. It is always the same temperature but the system turns off when the selected temperature is reached. Your car is similar with some additional features.

When you select any temperature on your ECC (Electronic Climate Control), 60, 65, 73, 80, etc. it doesn't mean that the discharge air temperature will be that specific temerature. They system will either cool or heat the interior to get close to the selected temperature and then will try to maintain that temperature. For example, if it's 100 F outside and the interior of your car is 130F, and you select 75 on your ECC (or even 80 on your ECC), the system will come on with the discharge temperature as cold as possible and the blower speed as high as possible. Lowering the temperature down to 65 or even 60 will not make the system blow colder air or have the blower blowing at a higher speed, it will already be working at it's maximum capacity. Again, it's just like your home. By lowering the thermostat, it doesn't change the discharge air temperature or blower speed. The system will simply stay on longer to get the temperature lower. It's the same with your car. By lowering the temperature on the ECC doesn't make the air come out any colder or blowing harder, but it will make the system stay on "FULL COLD" mode longer.

Where the difference occurs in your car is as the interior temperature nears the selected temperature, the system has the capability to change the discharge temerature (warmer or cooler), determine where the air will come out (floor vents, A/C vents, Bi-level,) and also adjust blower speed. Using the previous example, 100F outside, 130F inside your car, ECC set at 75F, your system will come on in the "FULL COLD" mode which means that the discharge air temperature will be at it's coldest (the coldest the system is able to produce) with the blower speed at its maximum. As the interior temperature nears the selected 75F, the blower speed will begin to reduce, the discharge air temperature will increase, until the interior temperature reaches the selected 75F. The blower speed will then be at its lowest with the discharge air temperature being moderate.

The system works the same in the winter as well. If the ECC is set at 75F, the outside temperature is 0F as well as the interior temperature of the car, the system will start out in "FULL HEAT" mode which means that the discharge air temperature will be it's warmest, the blower will be at maximum but the air will be delivered out of the floor vents. As the interior "warms up," closer to the selected 75F, the discharge air temperature will decrease, the blower speed will slow down, until again the desired temperature has been achieved. The air delivery might also change from the floor vents to the A/C vents or perhaps both.

That's why the system is called "automatic." The automatic climate control first came out in 1964 (coincidentally, the same time the Twilight Sentinel was first introduced). Cadillac used to advertise that when you first bought the car, you could set the climate control temperature and then never touch it again for as long as you own the car which is true. You can select 75F for example and also "AUTO" and then you would never have to touch the ECC panel again. The system would heat you in the winter, cool you in the summer, and maintain a comforatable temperature during mild climates. The only reason you would ever adjust the settings would be to slightly increase or decrease the temperature. The ECC is very precise to 1F. Adjusting 1F will change the way the system operates. Obviously there are extreme situations where you would want to adjust the system several degrees or you may want to decrease or increase blower speed, but for the most part, you should never have to adjust the settings. Even if it's the hottest day on record and your system is set at 75F, it will still come on at maximum capacity. Lowering the temperature to 65 or even 60 WILL NOT change the way the system operates during the first several minutes of operation (10-20 minutes after startup), only after the system "stabilizes" will increasing or decreasing the temperature cause any changes.

As for the mechanical problems you're having, it sounds like your system is low on freon. When the temperature outside is low and you turn on your A/C system and it is low on freon, there isn't much heat outside going across the condenser to increase the internal A/C pressure so your compressor will cycle quickly which will means that it will not cool very will and ultimately turning on your "A/C" message. When it's hot outside, even if your system is low on freon, there is enough heat outside which increases the internal A/C pressure which will not cause your compressor to cycle as quickly, which will cause your system to blow colder air but as the interior temperature cools off, the compressor will again cycle more because the air going across the evaperator is cooler now and then ultimately the sysem won't cool as well.

Max

Maximln
06-17-03, 07:23 PM
I was also going to point out that in all my Cadillacs, I usually set the temperature to 73 or 75F and then never touch it again. That began with the first Cadillac that I ever had, the 75 Sedan Deville. It had the rotating thumbwheel to adjust the temperature and I kept it just to the left of 75 (probably about 73) and set the lever to "AUTO" and rarely altered the settings. It's kind of cool, never having to adjust blower speed, temperature controls or mode. The system does it all for you--AUTOMATICALLY!!

I was also going to point out that automatic control only ranges from 65 to 85 on the ECC. When you adjust it from 65 to the next setting of 60, it goes to maximum cooling mode. Likewise when you adjust it from 85 to the next setting of 90, it goes to maximum heating mode. That means the blower stays on HI and cooling or heating is at its maximum.

Try a little experiment. Next time it's very hot outside, set the ECC to 60, start the car, and it will be in maximum cooling mode. As soon as you start the car, start increasing the temperatur 1F at a time going as high as 85. If its hot enough outside (which means its hotter inside the car), the system will not change at all. Throughout all the temperature increases on the ECC, the blower will still be at high speed with maximum cooling capicity out of the A/C vents.

Max

Night Wolf
06-17-03, 09:35 PM
Keep in mind, all this only works in AUTO, if you select hi or lo, then think of the number (for temp) as a lever in a car that controls the temp.... 70 and it will actually combin the heat and AC to make a temp of 70 to let out into the car etc...

But the auto thing is neat....although almost every car today has it.

Maximln
06-18-03, 03:48 AM
Keep in mind, all this only works in AUTO, if you select hi or lo, then think of the number (for temp) as a lever in a car that controls the temp.... 70 and it will actually combin the heat and AC to make a temp of 70 to let out into the car etc...

But the auto thing is neat....although almost every car today has it.

Panther--That's not exactly true. Selecting "HI" or "LO" changes the fan speed from automatic to a fixed high speed or a fixed low speed. In your car (and Ralph's car), there are 2 "HI" settings above "AUTO" and 2 "LO" settings below. The temperature of the discharged air is still controlled automatically by the system. If you select "HI" and select 75 as the desired interior temperature and the outsided temperature is 100F and the interior temperature of the car is 130F, the system will still go to "FULL COLD" mode which means the blower will operate at the fixed "HI" speed and the discharge temperature of the air will be the coldest available delivered via the A/C vents. As the interior temperature of the car approaches the selected temperature (in this case, 75), normally in the "AUTO" mode, blower speed would be reduced but in this case ("HI" selected), blower speed would remain at the fixed high speed but it will then mix warmer air with colder air to maintain the desired selected temperature of 75, possibly sending air to the floor vents or even to both the floor vents and the A/C vents. The system will still try to maintain the desired temperature but it is only able to control the discharge temperature and where the air is discharged. The reverse is true as well. If it's really cold outside and "HI" fan speed is selected, the system will discharge the warmest air possible and the fixed high speed to the floor vents. As the temperature approached the selected temperature, it will then mix cooler air with the warmer and probably send air to the A/C vents as well but still with blower blowing at full high speed.

The same is true if you select "LO" fan speed. Everything will still be automatic except that fan speed is limited to the fixed low speed so it will take much longer to reach the desired selected temperature.

Think of it like this. Your automatic climate control normally has 3 different ways to maintain the desired selected temperature--automatically controlling discharge air temperature, automatically controlling blower speed and automatically controlling the mode of air delivery (where the air comes out). By taking away the systems ability to automatically control blower speed, you greatly reduce the effectiveness of the system as blower speed is either always high or always low.

Another little climate control fun fact--even when you turn your system completely off, the blower still operates at a very low speed to circulate air and the system will still try to maintain the selected temperature that was last selected. Since cold A/C air is never available in off (the compressor is not activated), it is very hard for the system to do this but it does try. It will still heat the interior if it's really cold but would be unable to cool the car if it's very hot outside.

Max

Ralph
06-18-03, 05:00 AM
Yeah, that's one thing that throws me. Around town, in the last few days it has easily been 90 F outside, and in Auto mode, or Manual High or Low mode the AC is now ice cold! I just cannot understand why last month on the highway comming home, on Manual AC high setting it was just not cold, even at 16 C. From all your info, I must draw the conclusion that my freon is a little low, or it wasn't warm enough outside to warrent the AC to come on, since you said even in manual mode the computer still adjusts the temp. I liked my Merc Grand Marquis (1991 also) because you could also go full Auto mode or you had complete control and could even turn on the AC in the dead of winter to "condition" the compressor seals, etc. I suppose the real test will be this summer on the highway to our hometown to see our parents, if the AC can maintain cold the whole trip. :coffee:

Ralph
09-08-03, 01:08 AM
OK, we had another 87 F day here and we soaked up the perforated seats pretty good! On the highway, it worked going to the destination, but NOT comming back. Would this happen if the freon has slowly leaked out or ? I will probably wait until spring to fix it, if I still have it.

2dfx
09-08-03, 01:12 PM
OK, we had another 87 F day here and we soaked up the perforated seats pretty good! On the highway, it worked going to the destination, but NOT comming back. Would this happen if the freon has slowly leaked out or ? I will probably wait until spring to fix it, if I still have it.
Ralph instead of babbling over AC you won't need in a few weeks, why don't you go over to general discussion and explain to everyone why you disappeared and mysteriously came back?

Ralph
09-09-03, 02:46 AM
Ralph instead of babbling over AC you won't need in a few weeks, why don't you go over to general discussion and explain to everyone why you disappeared and mysteriously came back?

I know you are from the East, but you can still be polite!? There certainly isn't anything mysterious about it, unless you joined after early July. I'll just quickly babble out an answer right now, not that I have to justify myself to you. Without digging up too much dirt, I'll try to keep it peaceful. I got pissed off when someone called my front-wheel drive a "girls car" (I'm sure you know which thread I'm referring to). That shouldnot have happened on this forum IMO. That combined with a stressful situation at home, along with an unexpected career change, anyone can get hot under the collar. I'm not going to not let personal insults affect me too much, I deal with people's stress all day long, and my own, and it becomes a part of you as well. People can form any opinion they want of me, but to insult the most beautiful car in the world is criminal, and purely subjective of course. :D I'm not going to let one or two personal negative comments keep me from the new friends I have made here on this forum. I apoligize for my temper in the past and look foreward to learning much more about these wonderful cars we all drive. :bighead: (Even though I was defending myself and it turned into a grudge match) PS, maybe I lost my cool because my AC only works when the car feels I deserve cold air or not! :rolleyes:

2dfx
09-10-03, 12:20 AM
I know you are from the East, but you can still be polite!? There certainly isn't anything mysterious about it, unless you joined after early July. I'll just quickly babble out an answer right now, not that I have to justify myself to you. Without digging up too much dirt, I'll try to keep it peaceful. I got pissed off when someone called my front-wheel drive a "girls car" (I'm sure you know which thread I'm referring to). That shouldnot have happened on this forum IMO. That combined with a stressful situation at home, along with an unexpected career change, anyone can get hot under the collar. I'm not going to not let personal insults affect me too much, I deal with people's stress all day long, and my own, and it becomes a part of you as well. People can form any opinion they want of me, but to insult the most beautiful car in the world is criminal, and purely subjective of course. :D I'm not going to let one or two personal negative comments keep me from the new friends I have made here on this forum. I apoligize for my temper in the past and look foreward to learning much more about these wonderful cars we all drive. :bighead: (Even though I was defending myself and it turned into a grudge match) PS, maybe I lost my cool because my AC only works when the car feels I deserve cold air or not! :rolleyes:
Sorry to hear that! Hope things go better.

Come to think of that we almost got a fire started that involved elvis, soundadvantage, stoneage, and later on I added my piece, but it was eventually negated. Ralph they call it a girls car because they're too ashamed to know that RWD will be pushed out of existance! Be happy!

Mad'lac
09-10-03, 12:25 AM
Ralph they call it a girls car because they're too ashamed to know that RWD will be pushed out of existance! Be happy!


The hell you been smoking? They bringing them back as we speak.

davesdeville
09-10-03, 01:35 AM
And we're not starting that again...

Mad'lac
09-10-03, 03:18 AM
Nah....just letting him know that RWD is making a comeback. Nothing more nothing less.