Gjkdc

Hello Everyone,
I have a quick question. 2005 Maxima with 125k I am a bit ignorant when it comes to Auto AC systems. My ac was working fine. Than I noticed that,.. although it was still working, the compressor kept cycling on and off far too quickly. I checked the charge and the system seems to have adequate Freon in it. I also checked around with a black light and did not see any leaks illuminated. I am looking at replacing the pressure switch as it is an easy thing to get to. I have a few things that I want to check first like checking the compressor with a direct 12v supply of course but this part is crucial regarding my ability to swap the switch. Does the pressure switch have a schrader valve under it or does the entire system need to be evacuated first. If so I might as well just bring it into a service shop.

Any help is greatly appreciated,
Georgia is getting hot!!

Jerby

I think the easy to replace pressure switch that you're thinking about is located by the radiator on its left side, looking at the radiator standing in front of the vehicle, correct?
That one should be the high-pressure switch whose job is to prevent the AC compressor clutch from staying engaged when detecting too high freon gas pressure coming from the compressor located down below under the engine.

If you don't know how to check continuity with a DMM, Google it. Then pull that high pressure wire connector off and check the actual sensor terminals for continuity (non wire side). This video is quite helpful with what I'm talking about :
No point replacing this sensor by just winging it if it's so easy to check if it's good.

Gjkdc

Hello,
Thank you for responding. I appreciate the link. I will follow when testing the one already in place. If it has to be replaced do you know if a schrader valve sits underneath it in the fitting so that I do not have to evacuate the entire system when replacing it?

Thank you