Hello, I am new here but I am on some boating forums where there are some great sharing of suggestions on how to correct problems so I will give this a shot. I recently bought a 2006 QX56 Infiniti and love it. I noticed the AC was acting weird last week as it would turn on and act as if I had it on Auto. I DID NOT. After shutting it off and on a couple of times it would come back to normal. Today it went completely off. The AC, the Fan, everything. I pulled over and shut off the car and turned it back on. Still nothing. Driving home the fan turned on on its own. No AC but the fan was working. I then hit the auto button for the first time and the AC was back on. After getting out of Auto mode it ran normal for the remainder of the trip. Any Suggestions?? Thank you Coach Cap

could be anything since it s a used vintage car.

first thing is to check the obd port for any DTC's (fault codes). if you dont have a scan tool, stop by a local autozone. they should be able to check.

could be the HVAC cluster is faulty. dirt contacts, loose wiring under the dash... could be any number of things.

Thank you for the suggestions. I do have one of the computers to hook up. I will do that this weekend and go from there.

did you ever figure out what it was? mine is doing the same thing

charle, what model year? are you the only owner?

each situation is unique over another.

2004 qx56, i am the original owner. the AC just seems like it works when it wants to.

low refrigerant/leak?

clogged cabin filter?

faulty compressor?

any DTCs at the obd port?

had the system checked recently?

how did it work last summer?