a/c problems?

Check the head bolt threads. The threads on the block have been known to strech causing it to overheat. You have to drill, rethread and heli-coil it to repair. check out timesert.com under general motor kits to watch a video on the repair. I've seen a lot of N* engines that have had the same problem

This guide can help us fix it

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

Please run down this guide and report back.

for one thing dexcoolant is for 2000 and above, and he is right on the threads comming out of block, if its not leaking and fans run properly you have a headgasket prob,,

I have a 1999 Cadillac Sedan Deville. When I turned the air conditioner on for the first time this season I get nice cold air coming out of the vents on the passenger side and hot air blowing out of the two driver side vents. It was working just fine last year. Any suggestions, ideas?

[quote:47a125aeca="misslill"]I have a 1999 Cadillac Sedan Deville. When I turned the air conditioner on for the first time this season I get nice cold air coming out of the vents on the passenger side and hot air blowing out of the two driver side vents. It was working just fine last year. Any suggestions, ideas?[/quote:47a125aeca]

I don't have a cure, but my Cadi has the same problem

Took my car to Pep Boys today because I had a coolant leak and I thought it was the reservoir based on where the drip was. I was right.....couldn't believe it cost me $350 for a plastic jug installed. Anyway, when I left, my A/C was really warm and in a few minutes on the dash it said "low refrigerant...no A/C" and the compressor cut off and it was only vent air at that point. I was upset because my A/C has been fine for the 3 1/2 years I've owned the car and I also used it this morning going to the shop. I thought they probably allowed the refrigerant to escape to put in the reservoir so I went back a little bit angry. They checked the A/C System for leaks and told me my evaporator was shot. They could hear it hissing and it would not allow them to recharge with refrigerant. They told me they only pulled out 2 oz of refrigerant when they evacuated the system to install the reservoir. My A/C was really nice.....could it have been working so nice on 2 oz of refrigerant? Do you have any idea what my problem could be? They told me it's a 10 hour job to replace the evaporator because the engine has to be lowered and they don't do that. I'm a little angry at this point and confused!

I just posted a reply to your first question before you included these details. The system will not work on only two ounces of refrigerant. For all practical purposes, it's empty. Most systems on larger cars take around 1.5 to 3.5 pounds of refrigerant. The low-pressure cutout switch would trip before half of that was lost.

I would get a second opinion, preferably from an AC specialty shop or a radiator repair shop. Most of them do AC work too. If they too find the leak is in the evaporator, that is fairly common but there is no way anyone could cause it to leak intentionally or unintentionally. It is buried way too deeply inside the heater box. Chalk that up to a bad coincidence. Also, refrigerant escaping from there could take hours to leak out completely, and as it does it expands which is what makes it get real cold. That alone can make it look like the system is working. I recharged the system on my minivan years ago and was impressed when I saw frost coming out of the vents. It was really cold, but the next day it was empty. It was the escaping refrigerant that was making the "cold", not the system itself, and as I realized later, that frost was the refrigerant I was seeing. You can't SEE cold.

Sometimes inexperienced mechanics use the wrong terminology when they say "evaporator". If they are pointing to the unit in front of the radiator, that's the "condenser", and it is another common failure item. That one is relatively easy to replace. Since they said the engine needed to be lowered, (something I've heard about on some GM cars but have never done), that does point to the evaporator in the dash. On most cars the steering column is lowered and the dash assembly is pulled back to get the heater box out. It's still an expensive job on any car.

If the diagnosis IS for the condenser, have the mechanic point out exactly where the leak is. Typically it will be in a corner where the aluminum corroded. If it's in the middle in the front, it may have been hit by a rock. If it looks like it was hit in the back, I'd suspect the first mechanic hit it with a tool. The tubes on the condenser are pretty tough and accidentally bumping it would not damage it. They're also fairly well protected. The person giving you the second opinion will be better able to evaluate that kind of damage.

When I power on the car and turn the ac on It comes out the top vent not the the bottom blows cold just dont come out the regular vents any one knows what it could be

Do you mean it is coming from the defroster vent?

Yes sorry didn't read my question before I submitted it it comes out the defrost vents

Under the dash in the HVAC system are vent doors. They are what direct the air flow. I believe in 99, these vent doors were actuated by engine vacuum. Based on that, I feel there is a vacuum leak not allowing the vent doors to work. Check around for broken, disconnected, or damaged vacuum hoses. Also, there will be a supply hose that runs from the top of the engine through the firewall into the vehicle. Make sure it isn't disconnected or damaged.

I found a vacuum hose but dont kno where to find where it broke from to power the doors gor the ac vents

If you found the end hose, one way to get a general area it is , where was it sitting when you saw it? The area is usually around there close. the piece that broke off may still be on the end and you should be able to find it after some looking.

The driver side only blows warm air while it is set on auto and recirc. Cool air will blow on the passenger side. It has a separate control on the passenger side.

[quote:f80b2df54a="terryforsyth"]Air Conditioning problem
1999 Cadillac Deville V8 Two Wheel Drive Automatic 75000 miles
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The driver side only blows warm air while it is set on auto and recirc. Cool air will blow on the passenger side. It has a separate control on the passenger side.[/quote:f80b2df54a]


its low on freon, you have a leak

does not get cool already took to add freon but that did not work seems there is a block somewhere

Suggest take to a shop that specializes in AC work have diagnosis should be minimal charge the post results will advise.
Ask for High and Low side pressure readings

V8 front wheel drive automatic 51,000 miles.

compressor runs, blower blows but will not cool.

I would check the large tube refrigerant line coming from the firewall. If that is cold you have a blend door actuator that sounds like it is out here are two guide that will show you what you are in for when doing the job.

https://www.2carpros.com/articles/replace-blend-door-motor

and

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

Please let us know what you find.

Cheers

Hope this is not too late.

You will have to clear the AC codes before the compressor will turn on.

Turn ignition on hold down the "off" and "warmer" (red button) buttons on AC panel for a few seconds. The IPC will freak out for a couple seconds (it is a segment check for the IPC).

After codes are displayed on the IPC message center, you will see the message "PCM?". Press the up arrow (on the fan speed button) until you see ACM? Then press the down arrow.

It should now display "ACM Codes?" press the up arrow. After it displays the ACM codes, it will display "Clear ACM Codes? Press the up arrow and it will then change to "ACM codes cleared".

Now, press the Ooff button a few times to exit diagnostics.

Now your A/C compressor will turn on, as long as there is Freon in the system.

Hey,

Great addition to this thread! Please feel free to help out on the site whenever it can add information that will help.

Cheers, Ken

Air Conditioning problem
1998 Cadillac Deville V8 126300 miles
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The air is blowing hot air on the passenger side vents. The air is cold on the drivers side, it is only blowing hot air on the passenger's side.

Hey CADELANEY,

It sounds like you have a blend door actuator that has failed. Here is a guide that will help you get the problem fixed.

https://www.2carpros.com/articles/replace-blend-door-motor


Let me know what you find,


Best, Ken

When my car is sitting at an idle my ac will blow fine and get very cold, but when I hit the throttle the smallest bit and let off the ac clutch will disengage and start blowing warm. Give it a minute or so and it will start blowing cold once again. If I stay in the throttle say to 2K rpms or so it will start to blow cold then cycle off again. Freon is full, no leaks (that I can tell), high side pressure switch is brand new, low side pressure switch is new, and high side temp sensor is new, tried to put the ac module to "sleep" buy disconnecting the battery and ac clutch relay is new. Any help to get the ac going good in this S.E. Texas heat is greatly apreciated. Thanks in Advance!

hard do say without knowing what the pressure readings are when you are giving it gas.

it could be the pressures are wrong from having too much or too low of freon.

or the computer thinks that you are going to WOT and shutting off the compressor.

Air Conditioning problem
1998 Cadillac Deville V8 Wheel Drive Type unknown Automatic 103000 miles
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I have been to dealer, they just want to replace whole ac system but it works sometimes. I have a noise in the dash over by the glove compartment, it sounds like a little motor trying to do something. This went on for a while then the ac stopped working, it said "low referigerant". Sometimes I don't get the message but the system will only work on ECON. I had leaks sealed and it worked fine for one whole summer. Now, its happening again. I know ac system works. Is feels like a computer problem. At one point, one mechanic said he restarted the computer and the a/c worked fine. I live in Las Vegas so this is very important in summer. I already survived one without it. I also have a problem that the car stalls at intersections. This occurred after having new plugs. Mechanic restarted computer (whatever that is) and it was ok for a while but it's doing it again.

The A/C will not work with codes in the computer, it goes to economy, your leak is probably the evaporator, common leak point on caddies, if it is low it will set a code.

your stalling is probably crank sensors.

Scan codes, push off and warmer on the heater controls, with the key in the on position, write them down and post them here for me.

Hi Bob and Ken

My A/C was working and stalling problem wasn't happening for the last ten days, but it is again. Here are my codes

PCM P0603 History.
PCM P1527 History.
PCM P1599 History.
IPC B1552 History.
ACM B1348 History.
No SDM codes.
TCS C1255.
PZM B1552.
IRC B1771.
No RFA codes.
PCM?
IPC?

I think that is it. Thank you very much for any help you can give me with this. I would like to keep my car on the road and trying to get a mechanic to figure it out here in Las Vegas has been difficult. I am starting to think it is a short or something. At least the stalling is. It started after I got new spark plugs. A/C was on the blink before that. I have one other problem with loose battery connections. They loosen up after a few months and the car will not start until you jiggle them just right. I get them tightened and they are okay for six months.

Thanks a million. Have a great day.

PCM codes is what you want, and ACM is your A/C code.

the PCM 1599 is a stall code replace your crank sensors, a relearn will have to be done at the dealer.

the other PCM codes are

603 is PCM reset done.
1527 is transmission range switch.

the ACM needs reset to allow A/C to run
and be charged up.

reset all codes, after you scan code go to the three buttons up by IP and one of those will reset codes two of them will do nothing while in diag mode.

What wouldmake my passenger side not blow cold?

With dual climate control, you have two blend air doors that determine cabin temperature. Most likely, one of the blend air doors is not working or is stuck.

Air Conditioning problem
1997 Cadillac Deville V8 Front Wheel Drive Automatic

I am having problems with my a/c it is blowing cold air out of the passenger vents but hot air out of driver vents

suspect air -mix valve actuator
disconnect actuator and check blend door
if need to replace the actuator this is the steps needed

AIR-MIX VALVE ACTUATOR(S)
Removal & Installation
Remove glove box.
Unsnap rod from plastic retainer on actuator arm. Remove actuator mounting screws.
Disconnect electrical connector. Remove actuator. Check air-mix door for free travel.
To install, reverse removal procedure. If an actuator has been replaced, actuator needs to be recalibrated for proper travel. To recalibrate actuator, cycle ignition switch to ON position for 3 minutes.

Air Conditioning problem
1996 Cadillac Deville V8 Front Wheel Drive Automatic

how do i turn on air conditioner after recharging

Unless you have a hard fault that is causing it to default to econ, you can clear codes. First press off and warmer together. It will display codes on the info center. Let it run through the codes until it displays PCM/ECM?, press fan down until it reads ACM? and press fan up. It should display ACM CODES?. Press fan down until it reads ACM CLEAR CODES?, and press fan up. Cycle the key and see if auto can be selected, and the compressor engages. If it reroutes back to econ, you have a hard fault. Run the diagnostics again and report what ACM code you have set.

thanks for your reply gstacey

My brother and law has asked me to look at his Cadillac the A/C is not working. I do refrigeration in supermarkets, I do not usually work on cars. I could use some direction. This is what I have found so far.
On the dash the A/C controller will switch from heat to cool, but when you try to switch from Econ to Auto it will not. It always goes right back to ECON?

The system with nothing running static pressure is 120psi suc, and head, so I know we have some kind of charge in the system.

The LPS, and the HPS switches are all closed, but there are two other switches, they are on the liquid line, and it looks as if they are seperated by a metering device. I do not know why they are their, and I only have 4.9vdc coming to these switches when I unplug them and test.

Under the car on the compressor I do not have any power coming to the clutch.

I am not use to working on car units, and do not know if their is a control I missed to check, I find it odd the unit is stuck on the econ, becuase if it is like supermarkets we would be pulling outside air in and we would actually need automatic A/C on a hot pull down.

I would appreciate any direction. Thanks Tristan.

The two components in the liquid line are temperature sensors, they are 5-volt sensors, and yes there is an orifice tube in between them.

The fact that it is defaulting to econ, is a result of potentially false low refrigerant detection. The reason I say potentially, is a faulty switch or sensor can make the system think it is low, when actually it is not. You said static pressure was 120, at what ambient(outside) temperature were you at. If you were in warm ambient, the pressure could be that high in a low system.

Do this, press 'off' and 'warmer' together on the climate panel with key on until all the segments light and release. You just entered diagnostics and codes should display, you are concerned with ACM codes.

You can have two possible codes, a low and a very low. Not sure, but I think b1347/b1348 are the codes. If you push fan down, the dic should read 'PCM?'. Scroll with fan down until you reach 'ACM?' (or ACP) and push fan up. You will open the ACM possibilities to read data, clear codes, etc... Display clear codes, after you've read and recorded them, and push fan up. Codes cleared, cycle key, and you should have compressor operation, at least for a short time.

With manifold gauges installed, watch your low side pressure, and cycle time. If the pressure drops rather rapidly, and the compressor cycles rapidly, it is low on refrigerant.

the check cooling level come on every other day after i put cooling in. I do not see any liquid under the car
what could be wrong

If your actually having to add coolant, then there is a leak somewhere. You just have to find it. You will have to pressure test the cooling system to find it.