[99Classillac]

My 99 Deville is having a little problem I think. Air will not blow from the front dash vents. The air blows in the floor and in the windshield vents only. Also, I turned on the air recirculation button but nothing happened. Also, when I try to turn on just the windshield vent, nothin happens. I'm thinking maybe it is the door thing somewhere back there but I wanted to know exactly what it may be and where it is. Also, is it an easy fix?

And another thing, one side blows colder than the other side. Drivers side is colder. I checked everything. I checked the air mix door actuators, they both work. I disconnected them anyway and manually moved the rods and still didn't work. Is this related to previous problem above? Thanx

 

[Ranger]

Check for a vacuum leak.

 

[99Classillac]

What vacuum leak? In the engine area? What would the vacuum do with the A/C? I'm not being a smart ass or nothing, I really need your help. I didn't know there was anything that had a vacuum to control the flow of the air to certain vents. I thought it was just doors.

 

[Ranger]

I think the distribution doors are vacuum controlled (not positive on a '99). Get under the dash and look around. If it is vacuum controlled it will be obvious.

As far as the temperature differential, that is usually as sign of low refrigerant on a dual zone system, though not quite low enough to set a DTC.

 

[99Classillac]

I hope my system isn't leaking. I just put 2 can or 2 pounds of refrigerant in there last week. I cleared codes and the pressure reading was good right after I filled it. I'll check again to see if it's leaking.

 

[bschelle]

On my 99 Deville the A/C was only blowing out of the defroster vents. This is the default posistion when there is something wrong with the air programmer. It is located under the dash on the passenger side. It has a vacuum line coming into it from the engine and then there are four colored lines coming out of it going to the various vacuum door motors. The blue one is for the defroster/dash vent motor. I bypassed it and connected a direct vacuum line to it and now the dash vents work. But I do not have defroster vents now. I will just change it around in the winter! Worked for me.

 

[99Classillac]

Thanks for your help! So the air programmer just has to be replaced? Did you price check it yet? You know what the other colors are for?

Hey ranger, today my DIC told me that my refridgerant is low again, A/C off. I love it. I filled it last week and it leaked out again. I checked the pressure afterwards. It is low, but not totally all gone. I started probing. I cleared codes so AC would turn on temporarily. When it turns on, I hear a hiss from firewall area. I felt around and the high pressure line was really cold and starting to get frosty where the line goes into the area on the passenger side where the blower motor housing is. I removed some of the foam from aroung the line where it goes into the housing and felt down there and it was really cold. The rest of the line was not cold, just that area. Do I have a leak somewhere around there you think? The line went down too far and I couldn't stick my fingers any further to find the exact spot. I figured the extreme cold and frost forming on that part of the line indicated it was leaking near there. Otherwise the rest of that line would be cold too right? Someone at work told me that the heater core and the A/C share the same thing, just split into 2 parts so engine coolant goes throug one part, A/C refridgerant goes through the other part. He said that that may be bad. I never heard of a heater core sharing with the A/C. Is he right? Do I have to replace the heater core? He said I did.

 

[Caddyshack100]

99 before you do anything, first off run your codes to see if you have any, if your doors are screwing up then it will tell you. A programmer is very expensive, around 400 to 600 dollars, of course a wrecker will charge a fraction of that. On your vacuum leak, try looking on the right side fender where the vacuum ball/ is and see if that line is still on, then trace it back, because its under the battery, it could have broken, just a quick hopeful check instead of a expensive programmer

 

[Ranger]

Caddyshack is right. Programmers are very expensive, but also very reliable. I suspect a vacuum leak.

You obviously have a leak somewhere in the system. An A/C shop will have to inject a dye to locate it.

No, the heater core does not share refrigerant. You have an evaporator filled with refrigerant that the air passes through to get cooled and dried, then if heat is required, it passes through the heater core filled with coolant. Very similar devices, but very distinct and separate.

 

[99Classillac]

Thanks Caddyshack and Ranger. I checked codes and all I had was the low refridgerant code, and a left wheel speed sensor code(bad wire harness). Is the vacuum line rubber or something? What's a vacuum ball? I learn new stuff everyday here. I'm gonna go out today and take the battery out to see whats up.

 

[Ranger]

yes, the vacuum lines are usually rubber hose. I think the "vacuum ball" Caddyshack is talking about is a vacuum reservoir. I remember it on older cars, but haven't seen one in a while. Doesn't mean it isn't there.