A/C temperature adjustment.

[ryanprins13]

So at Westiva i was able to drive Ben's car Frito and tried it's a/c. It blew colder than mine and harder. Harder because i have a cabin air filter. I had brought along the same thermometer i checked my cars a/c temperature with and he checked his. Frito will get down to 34f, mine kicks out at 42f.
Then i drove Bob Kiddy's car and while i unfortunatly didnt try his a/c we started talking about it and he told me that to adjust the temperature set point there is a screw you can turn. But to turn it slowly and not far at a time or things inside will break. He did not remember which way to turn the screw for colder/warmer adjustment.
Does anyone know? Is this procedure described in a shop manual?
I will adjust mine and update this thread with how that goes but if anyone knows which way to turn the screw i would like to start in the right direction.
The screw is on the thermostat under the glovebox by the way. Here:



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[theastronaut]

Following! On my Miata I adjusted the cable housing for the temperature blend door a little to make sure it was fully in the "cold" position inside the evaporator box when the lever was all the way over. Made a slight improvement.

[william]

When I doubt crank it in! That should be up right? lol.
I really have no clue but it sounds good to me.

[WmWatt]

I'd search the Interent on air conditionmer thermostat adjustment. That thermostat is probably not made by Ford or Mazda and is likely common to other units which means there are likely other owners with the same question. Good luck.

[ryanprins13]

I'd search the Interent on air conditionmer thermostat adjustment. That thermostat is probably not made by Ford or Mazda and is likely common to other units which means there are likely other owners with the same question. Good luck.

Thanks! I will see if i can find a part number on it.

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[zoe60]

If this thread doesn't work search for "ac thermostat problem". I think you turn the screw CCW. Put some glue on it to keep it in place.
AC thermostat problem
Started by zoe60, 02-26-2012 03:55 PM
12

[ryanprins13]

Thanks! Its Here: https://fordfestiva.com/forums/showthread.php?t=41381
And you said to turn it to the left in there. So i will try that! Did you have to replace the switch in yours or did it keep working once you glued it?

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[zoe60]

It's been working fine for several years now. Mine did the same thing as yours, compressor kicked off too often for the car to get cool. Didn't replace the switch.

[Eaglefreek]

I've got dealer air and mine also cycles on and off quite a bit. I played with refrigerant volumes and no matter what, it would cycle and produce air that was 48 degrees. I jumped the wires on the cycle switch and it got down to the upper 30's then would freeze. I'll have to see if mine has that adjustment. With those lower temps of 34 and 42 degrees, are you guys still running R12?

[zoe60]

I have R12 in mine. Wanted to keep it original after I replaced the compressor.

[ryanprins13]

I've got dealer air and mine also cycles on and off quite a bit. I played with refrigerant volumes and no matter what, it would cycle and produce air that was 48 degrees. I jumped the wires on the cycle switch and it got down to the upper 30's then would freeze. I'll have to see if mine has that adjustment. With those lower temps of 34 and 42 degrees, are you guys still running R12?

Propane, lol.
When you stick the thermometer in the dash vents to check after it gets down to 48f and kicks out it warms back up to a certain temp then kicks in again till it hits 48. After its gotten there the first time does it cycle fairly quickly? If so its likely just that switch, not your refridgerant.

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[Eaglefreek]

It stays pretty much at 48. It might rise 2 degrees. It cycles quite a bit. This is when I'm driving. The AC doesn't cool very well at idle. I didn't see an adjustment screw on mine, but I was able to move the arm a little bit more towards cold direction when my control lever on the dash was all the way to cold. That might make a little difference, but it has been so hot and humid here that it doesn't blow super cold anyways. I'll have to test it when it gets a little cooler outside. I've got R134, because it already was switched over when I got it. I did try R152a aka computer duster, but it did cool as well as the 134.

[ryanprins13]

Thats very strange. Perhaps the thermostat is broken? I would think that if it worked properly it would keep the same spread of degrees where it kicks in and out. As in mine is 42-47 (5f spread) so i would imagine yours should be 48-53 if it was a properly functioning thermostat that was just set too high.

Again, If it cycles real fast i think its the thermostat, not anything else.

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[bravekozak]

I once owned an Iraqui Malibu that was wired not to cycle. It was meant for export to the desert where it would be on full blast all of the time. They were all equipped with big six cylinder axial A/C compressors. North American Malibus only had 4 cylinder radial A/C compressors. I suppose that if you want to test not cycling, just remove the two wires from the thermostat and plug them together with a double spade connector. Let us know if that works.

The main problem for everyone, is that there is no valve to block off hot engine coolant from flowing through the heater core.
The Festiva A/C has to continually battle heat from the heater core inside the blower housing.
I would install a heater control valve in the heater hose going from the engine to the heater core.
That will cool things down a lot!
A manual valve will look like this. You just have to find one for our hose diameter.
I have disconnected my heater core since I drive in the summer only.
Aloha.

[Eaglefreek]

I mistakenly put in the wrong temperature. Mine cycles at 58 degrees. I can hear it clicking. As mentioned earlier, I bypassed it and it stayed on until it froze up. I guess I'll install a new thermostat some day. I bypassed the heater core last year and it made no difference in temperature coming out of the vents.IMG_20170725_073943507_TOP.jpg