I've got two questions about two different auto AC conditions. 1. 2007 Nissan Altima In this auto the AC works sometimes. What happens is that it will be working fine then all of a sudden start blowing out unconditioned (warm) air. The refrigerant is good so I'm thinking this is a sign of the compressor going out. I haven't noticed any particular time the car starts blowing warm air. Is there anything else it could be? 2. 2003 Chevrolet Tracker. This auto cools fine when the outside temperature is 90 or below but if it reaches above that temperature it does not do a good job of cooling at all. I checked the refrigerant in it and it was fine as well. Not sure what else it could be. Any clues?
I have this issue in my truck. The freon blew out a few years ago, which was replaced with whatever they replaced freon with. Ever since, it's never cooled as well.
How are you checking the refrigerant? Putting high and low gauges on the system will also tell you if the compressor is bad. I am not sure how you can know the refrigerant is good but not sure about the compressor. What are your high/low readings and the ambient temperature?
I hook the tool up to the low pressure port and get the readings my auto and product says I should. I guess I'm confused on what this is checking.
I have a 2000 Altima. I'm not sure if they are exactly the same, but in my Altima, there is a thing called a "thermo control amplifier". (I just googled and the part does exist for the 2007 Altima as well). This is a little 30 dollar thermistor that sits inside the evaporator and shuts the AC off when the temp gets too cold to keep the coils from freezing. The part is notorious for going bad. The way that you describe the situation being totally random in nature sounds exactly like the thermo control amplifier. To test, remove the glove box and locate the evaporator. There should be a connector attached to the outside with wires three wires running into the evaporator. Disconnect the connection, and on the side that doesn't run into the evaporator, take a paper clip and jumper across the brown/red wires. The third wire should be green. If the AC stays on, the thermo control amplifier is your problem. It is a $30 dollar part, and attaches to a clip inside the evaporator. It is an easy fix.