I have an 04 350z, the a/c runs cold until I take the car past 5500 rpms at that point the air goes hot until I turn the car off. Once I restart the car the a/c goes back to normal. Does anyone know what is causing this and how to fix it?
Thanks

 

Simple answer.....turn the ac off before revving that high....then turn it back on.

 

Yeah, that doesn't work

 

Hmm... some carmakers have a feature that turns off the AC to reduce parastic power loss. The logic behind this is sound. If you're at WOT, you're making an emergency maneuver (merging, etc) and need all the power you can get.

It's possible the sensor or ECU is flawed. Are you aftermarket tuned?

 

The car is stock. I read through the troubleshooting section in the service manuel and I couldn't find anything that would give me any clues.

 

Compressor shuts down at WOT. Sounds pretty normal unless you are driving under normal conditions for a few minutes afterwards and it still blows hot.

 

It continues to blow hot until the car is shut off and restarted.

 

Hmm, then that certainly isn't normal. Does the compressor not come on at all after getting on it? Does it matter what position the A/C switch is on? (auto or not?)

 

The compressor doesn't come back on and I have tried it in all the different a/c settings.

 

You may have a problem with your A/C controller ( auto amp ). I hate to say this but it would be best to get it to a dealer or someone that has a Consult diagnostic tool. The ECU, BCM and A/C controller all share various data that decides when the compressor is to be switched on, the the ECU switches it on via the IPDM. The BCM and A/C amp both have their own diagnostic modes that can be accessed with Consult and you basically need to find out if it is an input or output problem.

 

Alright, Thanks Brett

 

No sweat man. Hope it works out. Let us know what you find, cuz now I'm curious.

 

It been said before but here is the FSM's description of the AC operation.


************************************************************ ***********************

• When the accelerator pedal is fully depressed.
• When cranking the engine.
• At high engine speeds.
• When the engine coolant temperature becomes excessively high.
• When operating power steering during low engine speed or low vehicle speed.
• When engine speed is excessively low.
• When refrigerant pressure is excessively low or high.

 

^My AC shuts off at low engine speed (RPM's) when I push the clutch in but I can't figure out why it drops so low every time