i have a 98 deville, heat works good. ac dont. system was charged, didnt help. no air will come out of the dash vents at all, be it heat or air. floor or defrost will only blow hot. any opinions?

 

Hey Water: Sounds to me that you have a problem in your air mix chamber.There are several flapper doors that have to work in sequence. The first is the mixture door which sends air over the hearter core or over the evaporator core. When the air gets over the cores ot either goes out the A/C outlet or out the heat outlet doors. Could be a door stuck which does happen because the hinges will rust due to the condensation in the chamber. Could also be the mode vacuum motor which closes and allows the A/C air to come out the A/C outlets and not the heat , defrost outlets. Check all your vac lines and check the mode vac motor which should be near the A/C module. To get at the mix door you usually have to go in through the back of the glove box liner area and you will see a cover for the chamber. Put your hand in there and see if the mix door moves freely, if not you can spray the hinge with wd-40 or similar to free it up. Good luck.

 

it certainly sounds like you know your way arond this stuff, thanks a whole bunch, i'll be followin your orders, i'll let ya know the results. thanks again.

 

the mode door is working fine, which tells me that i may have a second problem... if the mode door is working, wouldnt i still get conditioned air out of the floor and defrost vents? the door that isnt working is a kind of a flap door that is visable through the center vent. in the middle of the dash. this flap is not openning on its own.
even when i physically open this flap, my air isnt cold. i did charge the system myself,no cold air.

 

summer is here and lots of questions on the A/C coming up.

that you charged the system does not by any means equal that the sytem IS charged.
not enough details were provided.


why did you have to charge the system?
was it not working at all?
was it at least a little cold ?
was it leaking?
if it was leaking, did you do a UV Leak test?
is the compressor going on? can you tell?
is the orifice getting cold when compressor is running?

 

IMO, a '98 should have a good system without leaks unless it was seldom used and the seals dried up or
unless the "ambient control" was mostly on and the compressor wore out.

- if it needed refrigerant, it leaks. if it leaks, it requires overhaul of seals, hoses, fittings, or new o-rings.
- if it ran w/o refrigerant (and lubricant), you may have more serious issues with the compresor. it be
like running the engine w/o oil.
- if the ambient control flaps are not working, you either gotta fix them or jamm them in the desired position,
at least to check for cold air.
this may be more than a over the net fix it. i be getting it to a local A/C shop or two for an estimate
and a 2nd opinion. there is only so much one can do w/o proper equipment and limited skills.

this makes me wonder, do most people know that the refrigerant carries with it the OIL and running with
low or no refrigerant is running w/o enough oil?

the adding of "stop leak" to the radiator was for a leak? or are we talking about the coolant supplement ?
probably nothing to do with the A/C but concerns me more.

note:
i have two vehicles that will turn 20 this year and are closing in to the 200,000 mile mark. i make sure the A/C
runs at least once a month for 30 minutes, and i only turn on the "ambient controls" on when i need COLD air.
this way, compressor has minimal use and seals are lubricated annd conditioned often. original compressors
and no leakage to date.










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im takin her in to be looked at, thanks a whole bunch for the replies. one other thing , what does control the flaps , mechanical... va***e... what could stop them from opening?

 

not sure what type yours has.
- there are electrical units with solenoinds that fail or blow fuses,
- there are vacuum controlled units with actuators that fail or vacuum hoses that develop a leak
or got disconnected - most likely your type.

- then there is the pivots/hinged spots getting sticky. kind of like a house door that needs WD40?
- then there is the "got jammed" with debri issue. that can be anything that the blower can inhale
if the filter is missing or damaged to remants of foam or gasket mtls that can manage to get loose
and jamm the gates.

maybe Katz or FLCaddy can shed some light on this area. they know these spots much better.

keep us posted as to the estimates and outcome.

lastly, did you find out why the "stop leak" was used ont he radiator?








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