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Jay, Nissan Technician
Category: Nissan
Satisfied Customers: 20510
Experience:  20+yrs experience with Nissan & Infiniti Trained & Certified.Currently still working for Dealer
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AC compressor not always activating. High and low pressures

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AC compressor not always activating. High and low pressures are normal, cabin filter replaced.
JA: How many miles are on the car? How has your mileage been lately?
Customer: 120,000 miles and mileage has not changed at all. Flat ground on Florida coast= 22-24mpg
JA: What is the model/year of your Nissan?
Customer: 2006 Murano AWD
JA: Are you fixing your Murano yourself? What have you tried so far?
Customer: Yes, I am a DIY guy. Changed cabin filter and checked pressures with manifold guages per service manual specs. All pressures are within normal limits.
JA: Anything else you want the mechanic to know before I connect you?
Customer: Had same problem a year ago and took it to mechanic - he purged the system and vacuumed and replaced refrigerant. Worked OK for a couple months, then has slowly deteriorated to this condition. Acts like it needs a charge but am afraid to overcharge.

Hello my name is ***** ***** thank you for your question.

What are the AC pressures reading?

Customer: replied 2 months ago.
High side is 200 and low side fluctuates between 41 and 45

What is the outside Temperature?

Customer: replied 2 months ago.
It is late for more work in the dark tonight. I would be ok with a call tomorrow or a list of things to check before the call.

We can continue tomorrow if you like..

Customer: replied 2 months ago.
that would be great. Anytime after 9:00 at your convenience.

Just hit me up online here around 9 or 10 and I will reply as soon as I can. ok?

Customer: replied 2 months ago.
Alrighty - thanks, Jay

Your welcome!

Customer: replied 2 months ago.
Jay, good morning. After my last message last night, I pulled the car into the garage and turned on the AC one last time. It worked great while idling. So, this morning, I have been out driving around with a digital thermometer in the vent. The temp gets all the way down to 45 degrees and stays as long as I leave Auto function off and temp of 60 degrees selected. When I turn on Auto (which always used to work), apparently some warm air starts mixing with the cold and my digital readings start climbing into the 60's and 70's; and then, it never recovers. All in all, I am happy with the system and will use it this way until I can figure out what is happening with the 'Auto' function.

Thank you for that description. That helps me.

Under the drivers side dash area, the trim panel by your knee's. You will see a very small vent or grill that is maybe as high as a quarter. Behind that is the incabin temperature sensor. Can you lower that panel and let me know if the hose is connected to the sensor and if the sensor is plugged in?

Customer: replied 2 months ago.
I knew that was there and blew it out yesterday. I will lower the panel and get back to you.


Customer: replied 2 months ago.
Wow - that was an ordeal. The hose was attached, so I removed the sensor to inspect and found the thermistor to be caked in grime and dust. Qtips and alcohol later, It is ready to reassemble, but it is raining. When I get it all back together, I will road test again and get back to you. I used to have a large garage and I really miss it.
Customer: replied 2 months ago.
Well, happy to report that, after a long test drive trying to get the system to fail, it is working perfectly - on Auto or manually. Hard to believe that a dirty sensor could make a difference like that. Maybe it was a combination of things, but regardless, it is working. I never would have gone back to that sensor after blowing it out yesterday, so I am grateful that you led me there. Have you seen similar results in the shop, Jay?

That incabin temp sensor as you can now see plays a big part of the Auto Air system. The Sensor is very sensitive.

I am glad I was able to point you the right direction and help resolve your issue!

If you have any more questions on this, please feel free to ask.

If not, and you're satisfied with my help, please Rate me by clicking the Stars on the top of the page. That is how I get credit for my work. I hope I have provided you with 5 Star Excellent Service.

Thanks Jay!

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