The Nissan Path

Our A/C quite working a few days ago. Which sucks because its close to 100* outside!! I need to fix this quick. I check the compressor clutch, and it seems to not be engaging on & off like it should. I tapped on it with a hammer a few times with the engine running & ac on to try to get it to engage with no luck. It was working perfectly moments before it quit. Should i just replace the clutch or the whole compressor? thanks

It may be neither! If the refrigerant is leaking and has gone too low, the pressure switch will keep the clutch from engaging. A bad thermistor (sometimes called a thermal amp), which is attached to the face of the AC evaporator core, can also interrupt power to the clutch, among other things. The system needs to be properly diagnosed; the first thing that should be done is a set of gauges should be installed to check the system pressures. With the compressor not running, the static pressure should be around ambient temperature and a full system usually shows at least 70 PSI on both high and low sides. Of course, with the clutch engaged, these pressures will change drastically if the compressor is good. Low side will operate around 40-45 PSI and high side, which can vary depending on a number of variables including temperature and humidity, can operate in PSI from the high 100's to low-to-mid 300's. An AC performance test is listed in the factory service manual which takes into account these variables and gives specifications as to what the pressure range should be.
Another thing you can do to test the clutch and part of the system (temporarily) is run 12v of power to the clutch harness connector. If the clutch is good, it should engage and turn the compressor shaft. Keep in mind that the system should not be left like this, as this bypasses the protection systems in place to prevent damage to the compressor by shutting it off when the pressures get to high or too low.

I found out why our A/C quit working. The electromagnet on the compressor clutch went bad. So it wasnt pulling the clutch in, to engage. For the price of the parts, I just ordered a whole new compressor and am waiting for it to arrive. Ill post back once it's installed.

FIXED!! I had the new compressor installed today. Works perfect!

Good to hear! I actually had the same thing happen on my 2006. In my case, I purchased the A/C clutch assembly for $110 off of Ebay and replaced it. It wasn't so bad of a job; it can be done without discharging the refrigerant and without removing the compressor. I removed the fan shroud with electric fan, drive belt and possibly the fan blade...as well as the lower skid plate. Been working fine ever since!

Well here we are again!!! It got hot the other day and my wife kicked on the a/C and it didnt turn on AGAIN!!! This was the first time this season she tried. We've only had the new compressor on there for one summer!!! I haven't had time to check it out yet, but this is ridiculous. I seriously hope it is just low on refrigerant.

Well, if it is low on refrigerant, that would suggest you have a small leak in the system, somewhere. Leaks, at times, can be just as hard to diagnose as component failures. Look for oily or a mix of oil and dirt at the A/C line connections and on the core of the A/C condenser.