A/C blowing hot air

Tiny
BLAZ85
  • MEMBER
  • 2018 NISSAN NV
  • 5.6L
  • V8
  • 2WD
  • AUTOMATIC
  • 22,816 MILES
Our church has the above nv3500 van. Equipped with the automatic climate control system and rear air. Suddenly it started blowing ambient or slightly cooler air even with the temperature settings at the lowest.

I put my gauges on it and with a 90 degree ambient at idle I had 32 low and just under 200 high, both rock solid. Condensate was flowing profusely from the drain tubes of both evaporators. My first thought was the blend door actuators but it is unlikely both would fail at exactly the same time. I then took and raised the temperature setting to the maximum. The system responded by providing extremely hot air. I tried it on both sides and both responded the same; so the actuators' are working. It almost seems that the blend door actuators have gotten out of sync with the temperature setting or the air is somehow getting reheated after it passes through the evaporator coils but before exiting the vents.

I have two questions, first, what are your thoughts on this? Second, is there a procedure for recalibrating the blend door actuators to match the temperature settings?

One other observation, with the same temperature setting, the passenger side vents will blow about 5 degrees cooler air than the driver vents but that has been the case ever since we have had the van (about 3 months).

Thank you in advance for you response and thank you again for the times you have helped me in the past.
Friday, July 30th, 2021 AT 8:46 PM

6 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,747 POSTS
Hi,

I suspect you are low on Freon. At 90F, low pressure should be between 45-55 and high should be 250-270. When they are both low, that indicates (in most cases) low refrigerant.

I would recommend charging the system based on the readings. Here are two links you may find helpful as well:

https://www.2carpros.com/articles/air-conditioner-how-to-add-freon

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

Since it is likely just low, the first link should do the trick.

Let me know what you find or if this helps.

Take care,

Joe
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Friday, July 30th, 2021 AT 10:34 PM
Tiny
BLAZ85
  • MEMBER
  • 50 POSTS
As usual, you were right on. It was just low of refrigerant. I added until the pressures were approximately what you stated, slightly lower due a lower ambient of 84F. At 1,500 RPMs after stabilization, it had a center vent temperature of 38F. Sometimes I have a tendency not to check the basics.

Thanks so much for your help!
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Tuesday, August 3rd, 2021 AT 8:24 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,747 POSTS
Hi,

First, you are very welcome. Thanks for letting me know. I'm glad it took care of things for you.

Please feel free to come back anytime in the future if you have questions or need help. You are always welcome here.

I don't know if you would consider it, but would you rate our site? It would really be appreciated. Here is a link that takes you to it. If you don't want to, that's no problem whatsoever.

https://www.sitejabber.com/reviews/2carpros.com

Your consideration is appreciated.

Take care of yourself.

Joe
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Tuesday, August 3rd, 2021 AT 10:41 PM
Tiny
BLAZ85
  • MEMBER
  • 50 POSTS
Joe,

I have tried twice to write a review as you requested. However there seems to be a problem with the form. I cannot give the forum a rating. When I click on "Click to Rate", nothing happens. Even though I have the "Title" and the narrative completed, it will no accept review without a "Rating". Am I doing something wrong or is it the form? I will be happy to write a review if we can get this worked out.

Thanks.
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Friday, August 6th, 2021 AT 7:08 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Thank you.

I will forward this to the admin to help you.

Roy
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Monday, August 9th, 2021 AT 3:14 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,602 POSTS
They must have something wrong with the site which is fixed now, click on the write a review link. Let me know.
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Tuesday, August 10th, 2021 AT 8:57 AM

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