Stereodude

Now that it's a little warmer in Michigan I've been driving with the A/C on. I have a 2002 SE with the automatic climate control. I've read some threads that say the compressor for the A/C does not cut out at WOT if you have the automatic climate control. I know if definitely cuts out at points, but I would have to agree that it isn't linked to WOT. My current theory is that the compressor disengages when the secondary intake runners open up at 3800 rpm. I'm not 100% certain about this, but it seem to be the best pattern that I can observe. Anyone else know if this is correct?

Stereodude

edadams

I have noticed this in my altima also, the A/C mysteriously turns off above 3900 rpm and will turn on after the rpms stabilize.

Stereodude

So, if we're correct that means you aren't going to have AC above 97MPH (3850RPM in 5th). I can't have AC above 117MPH (3850RPM in 6th). How disappointing.

Stereodude

Stereodude

*bump*

I know someone else with a 2k2 has to either know this or be interested in this conversation.

Stereodude

ajahearn

iTrader: (3)

I've been checking through the ESM (service manual) and apparently the setup is different for an Auto versus a M6. The compressor uses a magnetic clutch. I can't find any specific speed references but there is a comment under the clutch that the "Refrigerant pressure on suction side is low during high speed driving or when ambient or interior temperature is low." They apparently have a little LAN setup for the AC system which involves a set of temperature sensors, ECU, etc. There are references to low engine speed but nothing about high RPM's. There is some info about air intake sensors which may be why at high rates of speed it shuts off.

Eric

I've noticed this with both my 2k and 2k2 Maxes. Under hard acceleration, the A/C seems to stop because the air suddenly comes out quite a bit warmer and then cools down once I stop accelerating.

I'd always assumed it was due to the car being smart enough to realize that all the power should be sent to the wheels and shutting the AC off temporarily.

Stereodude

Most cars do it at WOT. The 02 Max clearly isn't doing that. I'm almost certain that at 3800-4000 RPM when the intake runners switch the AC compressor kicks off regardless of the throttle position.

Stereodude

soundmike

iTrader: (24)

Hmm, i never really tested it officially. But on a hot day i normally try to keep the revs up so that the a/c blows better.

ajahearn

iTrader: (3)

I thought it was common for all AC compressor systems to have a clutch. The clutch is there to disengage when there is insufficient speed (underdriven) or too much speed (overdriven). So under WOT isn't really the issue as much as the RPM's.

I'm not a mechanic, this is just my understanding of how the system works.

NYC2SD

I always thought it was related to the angle of the throttle (according to the throttle position sensor) In the 2K2 this may be different due to the drive by wire.