2000 Manual A/C intermittent

I have checked the pressures, and even replaced the pressure sensor.
The main symptom is the light on the a/c button turns off and the A/C turns warm. It will run all day at idle and high or down the road at med.

It kicks out when the pressures are fine and when it kicks back in sometimes it kicks back out immediately, even before the gauge has time to move.

Looking at the diagram, the light appears to be controlled by the module itself and not by the PCM. This leads me to believe that the module (that doesn't have any external inputs) is the problem.

Does anyone have a verified repair for this?

I've done a few dozen fixes like described below- very common Malibu and Intrigue problem-- the very grease that is supposed to aid the contacts actually causes the issue- it turns to earwax gerts hard and causes the issue.. see fix in link below

http://idle-hourranch.com/AC_ControllersAreRepairablemalibuintrigue.pdf

I believe to check this, you need a scan tool......basically the control head, when you push the A/C button, sends a "request" to the PCM to ground the A/C clutch relay......if the PCM no longer receives that request(the light goes out), then the PCM disables the the relay....touching the A/C button on/off/on should have a likewise request reading from the scan tool....

The other possibility is that even though you have replaced the pressure sensor, you don't know if the PCM is reading data from it, or if it is intermittent.....

So, to really check this out, you need access to a scan tool capable of reading these inputs...

No scan tool required- just do the fix described-- I do them in the parking lot at work...in 10 minutes.....with just a few simple tools.

No scan tool required- just do the fix described-- I do them in the parking lot at work...in 10 minutes.....with just a few simple tools.

I actually just picked up a used one from the salvage yard. I will try that and see what happens first.

Have you ever seen where the fan speed will die down under half throttle?
I usually see it going up an on ramp with the fan on full. Doesn't appear to be Battery voltage related.

Well, I installed the used one I picked up and it was even worse.
Just touching the blower switch would make the A/C light turn off.

I did the repair and it works great.

I do still have that problem where the fan speed decreases while on recirculate and I am driving up a hill.

It's not the fan speed- it just sounds that way- it is the lack of a good vacuum to the mode door- as you excelerate up a ramp- the engine has less vacuum to offer and since you have a leak in your vacumm line, it releases the spring loaded door that defaults to defrost- your air is flowing through the vents- then when you tromp it- the air goes to the floor and then to defrost if you vacuum leak is bad enough-- with no vacuum at all the air flow is to the defroster (for safety reasons- in winter especially) so follow the black plastic vacuum line underhood from intake manifold to your vacuum reservoir and fix the cracked plastic tube by splicing in a rubber hose- windshield washer pump hose works good.

Seeb it hundreds of times- black plastic vacuum line cracked or check valve inop...

Yes it certainly does seem like that, but this is not a vacuum operated control head.

Just because the control head has no vacuum selector switch does NOT mean you don't use vacuum to control the 3 mode doors. Your system uses an electrical solenoid vacuum module- to control the mode doors. It is mounted near (below) the HVAC box. All Data clearly outlines this in the HVAC control diagrams. Your vacuum source hose is purple-underdash and underhood it is black- trace it to the vacuum reservoir- mounted behind driver's front fenderwell as I recall. If you want to solve your issue please use my advice. Been there, done that.

http://idle-hourranch.com/2000intrigue.JPG