# Air conditioning issues not normal !



## RestoRider/AltimaGXE (Apr 14, 2017)

Hey guys, Sorry I had to rest up a bit. My old pc was dying so I had to get another one
and then go through all the change over. PITA. Well I'm back on board now. 

Lots have happened to my nissan since I last posted. I got new belts install, New window tint
And an A/C recharge with about 8 oz's of freon. The problem was that the A/C blew cold as long
as the car itself was cool. Worked fine. But if the inside of the car got hot. It took forever for the
car to blow cold air some times not at all. It was like the compressor would not stay on. 
Well I did some research and found out why. 

There is a thermistor sensor that is used as a compressor clutch relay. So it mounts in the box cover
that surrounds the Evaporator core under the dash. So it senses the air temp and keeps the compressor
on while the car cools off. If this malfunctions the action of the compressor can be very erratic. 
Not an expensive part. But it is a bitch to replace. I have mine ordered along with a new radiator and hoses.
Seems my radiator has a small crack right in the top just left of the cap. So all new hoses and the radiator
were just a shade over $100. I get to do the install. and swap out the Thermostat as well.


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## smj999smj (Jan 1, 2006)

Actually, the thermistor---also known as a "thermal amp"---is used to sense the temperature of the evaporator core and if the evaporator freezes up, it will open the circuit to the compressor clutch to keep it from engaging the compressor. Yes, it can fail and also if put in the wrong place in the compressor core, it will also cause A/C performance problems.


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## RestoRider/AltimaGXE (Apr 14, 2017)

The idea was to convey that the issues with your A/C system might not be related to low
Freon and can be caused in part by this $13 part that senses the inner air temp. 

When my car is hot inside I can turn the A/c on max and I can see the compressor turn on and off
about 10 times within 20 seconds. When the car is dead cold inside like sitting overnight
you can do the same test and everything works as it should. So you must know how to 
change this part out so post some details on testing and replacement. Others might need it. 

jake


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