A/C not blowing cold, but pressures are fine

Hi All,

Ran into a problem with The Vixen a few days ago... the A/C is actually blowing warmer than just the vent.

Checked out the pressures, and it all seems fine. Running R12, and have about 30 on the low side, 185 on the high @ about 85 degrees outside. The compressor kicks in and cycles fine. It allworked fine last year

I did replace the hot water / heater valve last year, but I think even if that was stuck open it wouldn't make a huge difference (IIRC, that valve only applied when A/C was on Max)

Am I forgetting about a blend door or something similar that may be stuck?

Been a while since I have dug in that far in the dash so my memory is foggy.

Thanks for any help y'all can provide!

-Dave

Normal pressures and normal cycle but no cooling....Don't know how that can happen. Does the low side pipe/hose feel cold when running the AC?

All I can guess is to evacuate and recharge.

Dave,

Have you verified the Hot / Cold control is moving properly Left/Right and that the cable is attached to the door mechanism.


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Quote:

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Originally Posted by DMC5180

Have you verified the Hot / Cold control is moving properly Left/Right and that the cable is attached to the door mechanism.

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The temperature knob appears to be moving normally. I don't recall where to find the other end of the cable though. Where can it be checked? i.e. where is the other end?)

The other selector (mode switch) works fine and the blown air directs to the appropriate outputs as it should when the switch is moved.

I didn't check the hose temperatures, actually -- didn't think about that. I just checked the pressures.

Unfortunately it in a tough location under the housing. I would think you should be able to see it if you pull the carpet back and look under the housing in the vicinity of the drain connection.


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Having a look at the parts diagrams, it looks like it attaches to the temperature "valve & trunnion", which by the shortness of the cable must be within a foot or so of the selector, so I'm guessing it is behind the HVAC controls, near the firewall, somewhere on top of the frame hump.

[Edit] Thanks, Dennis. I will see what I can find there.

For all of our cars, the A/C system cycles the compressor on and off based on load, correct? Meaning, if there is more heat to be removed (producing cold), it works harder. Outside temperature, RPM of the engine, whether the car is moving or stationary. They all factor in.

If your A/C system is indeed working normally, and those pressures are where they should be, that cold must be going somewhere, right? If there is no heat being removed and no cold being produced, you would see it in the system not working hard at all. If the system is working hard(-ish), then you should be able to feel around either the cabin or outside and upfront by the passenger wheel well and locate where your cold is going.

If it is a problem with one of those air directing flaps not working, and the cold is still being created, it has to be going somewhere and you can probably find out by feeling around for it.

Found the end of the cable and the lever it's attached to, visible by pulling the carpet back a bit on the hump in the passenger footwell. The movement there looks just fine, so it must be something else... any suggestions?

Quote:

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Originally Posted by Project Vixen

Found the end of the cable and the lever it's attached to, visible by pulling the carpet back a bit on the hump in the passenger footwell. The movement there looks just fine, so it must be something else... any suggestions?

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Are the fans cycling? Also put your hand on the accumulator while running A/C. It should be very cold to the touch. If it isn't, I'd say your just low on Refrigerant.

Your high side pressure is about normal so that suggests you have enough R12 but it does not make sense your not getting cold air.

Now if it was cycling at a short on time and long off time than that would suggest a plugged orifice.