Serious HVAC problems

stan wrote:

1999 white diamond dust,SC.

Well, right there is one good thing... If you had a '95, you'd be dealing with a whole different, less common and more antiquated ECC!

Hey Thanks Mark-perhaps i need to replace the HVAC head unit...

stan wrote:

Hey Thanks Mark-perhaps i need to replace the HVAC head unit...

You're welcome - but no, the head unit is the least likely problem. All the thinking is done in the programmer, down by the PCM. And a lot of the time, the outlet temperatures are different on the driver's 4 registers and the passenger's 4 registers, which usually means a problem with the blend-air door actuator motors or position sensors. Hell , I suppose a bad solar sensor or cabin-temp sensor could also be a suspect... You'll see a lot of this in the other threads.

You are sure, right, about your refrigerant and compressor?

ohh yeah the compressor is working fine but i think you are right thinking of the PCM.This weekend i should take a look at this acuator motors or at least ask my buddy what to do,but if it's like you say a bad solar sensor then i don't know ....haha.............we'll see.Hopefuly it ain't that serious.

First thing I'd do is lock the blower in 4th or 5th gear, and then run the Temp from 90 degrees down to 60 degrees and see if one side is cooler than the other... If they are both the same, then you're looking for something that would affect both sides equally, rather than a single bad actuator.

G'night.

ohh thank for the tip-will do that,but when i was testing the temps they were all equal.It's all bad....
OK Mark thanks and goodnight.

stan wrote:

ohh thank for the tip-will do that,but when i was testing the temps they were all equal.It's all bad....
OK Mark thanks and goodnight.

If the AC compressor is running, you'll see/hear the clutch engage and turn.

If you refilled the AC with cans (instead of evacuating and recharging) that may aggravate not solve the problem, system may be mis-charged (over or under-filled).

If the AC compressor is working and the system is properly evacuated then lubricated and recharged, and you are still not getting adequate cooling, then there may be other problems:

- if the ambient temperature is over 100F you may need a different orifice valve to deal with it. This would happen if you say lived in Flagstaff AZ (or someplace else where ambients run lower) and moved to Phoenix ( - - ) (or someplace else where ambients run over 100F part of the summer). It's been hot lately. TO put this in requires evacuation, purging, install new variable orifice valve for 100F+ ambient (and probably a line filter), then recharge.

- if the ambient is less than 100F your blend door could be stuck with debris (less likely) or dying actuator (more likely) and using the search function you will find good write-up on how to deal with that blend door thing and even I think a picture or 2. To fix the blend door actuator is tedious,a dn it might help to take out the passenger seat to get room to work (not necessary, just helpful).

Albertj