Diagnosing Your Nissan Maxima AC Compressor
Your car's cooling system depends on several interconnected parts-one of them is the Nissan Maxima AC compressor. Located at the core of the A/C unit, it is responsible for moving refrigerant gases throughout the rest of the system. Without this component, you won't have cool air circulating in your car. In order to prevent an uncomfortable riding experience to yourself and your passengers, always be on the lookout for these symptoms and repair the AC compressor as soon as possible.
If you hear a tiny scraping sound right when you turn on the AC unit and it goes away at the exact time you turn off the component, then the compressor clutch needs to be replaced.
Clutch operation problem
If the clutch operation is not coming on when you turn on the AC unit, test the clutch by applying power directly to the wire on the top front of the compressor. If it comes on with the direct power applied, then there might be an electrical problem. Check for a blown fuse. However, if it still doesn't turn on, then you have to replace the clutch.
Loud knocking noise
If you hear a loud noise when you turn on the AC unit, then this means that the AC compressor is on its way out and needs to be replaced as soon as possible. Do not use the AC until you have bought a new stock as the vanes inside the old one should be coming apart-which explains the noise. The more that you use the AC, the more materials will be released into the cooling system, which would thus cause a blockage. This could get very expensive as you will need to replace all the components in the system by then.
AC compressor not working
Hook up the gauges to the cooling system and turn the AC on. If the AC compressor does not come on, check the pressure on the gauges. The low-temp (blue) side should be around 75 to 80 pounds in order for the component to operate the low-side switch and turn the compressor on. If the pressure is below that mark, then the system should be charged in order to get the switch activated. The low-side switch is there so that if the pressure drops below 75, it shuts down the AC compressor to prevent damage. On the other hand, if the pressure is within the 75- to 80-pound mark but the compressor isn't working, then there may be an electrical problem.