AC/HVAC system from hell. Everything works no cold?

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latlog7
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AC/HVAC system from hell. Everything works no cold?

Post by latlog7 »

Low pressure line is ice cold, high is hot, ac clutch engages properly. I recharged the system since it was a tad low. No leaks. When set to cold, it comes out warm. When set to hot, it comes out HOT. I checked all blend door actuators and they spin, along with the pieces they are connected to. Even mode actuators work too. So even more evidence that blend doors are working. Does anyome know what else could i possibly look into? Ive even tried trying a million different combinations in hopes something was just mixed up.
Im nearing insanity, thank you so much in advance.
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Sirius
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Re: AC/HVAC system from hell. Everything works no cold?

Post by Sirius »

It is possible that the blend doors are not moving through their full range of motion, even though they are moving. There's a big plastic gear in the actuator that splits where it engages the motor shaft. If there is enough resistance on the door at a particular spot the gear may slip on the shaft and the door will stop there. Going back the other way (toward hot, let's say), the resistance is not encountered and the door actually moves until it hits a new resistance, presumably the full-hot position. There is a techinfo article that kinda goes into detail on the failure mode that may be of interest to you.
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AJT2004
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Re: AC/HVAC system from hell. Everything works no cold?

Post by AJT2004 »

What are the high and low pressure readings?
Although the line is cold the refrigerant level may be incorrect and/or have air & moisture in the system due to improper recharging. I would recommend evacuating the system, pull a vacuum and then add the correct amount (weight) of 134a. IIRC the A/C blows colder with 8 ounces more than called for.
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nos4blood70
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Re: AC/HVAC system from hell. Everything works no cold?

Post by nos4blood70 »

How sure are you that the system charge is good?

The AC performance is a lot better at 2.5 versus 2.2 pounds as mentioned above.
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latlog7
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Re: AC/HVAC system from hell. Everything works no cold?

Post by latlog7 »

Sirius wrote:It is possible that the blend doors are not moving through their full range of motion, even though they are moving. .... There is a techinfo article that kinda goes into detail on the failure mode that may be of interest to you.
Excellent idea, thank you so much. I have a shop looking at it now, but i think theyll be stumped. I read a tech info that helped me locate the actuators, but i couldnt see the actual blend doors. I was able to see the plastic looking levers moving. Do you know if theres a way to manually adjust them or pry them in a certain direction without taking apart the whole dashboard?
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