After changing the alternator for the second time, not the ac blows hot. Fans come on when I turn ac on, but clutch doesn’t seem to engage. This did not start til after alternator swap. Could there be something I haven’t hooked back up?

Not on the alternator, but if you had the condenser loose then you may have forgotten the Refrigerant Pressure Sensor on top of the drier bottle. If that's flatlined then the ECM won't let the compressor switch on.

As you prob know, the alternator job on the pathfinder sucks. I can’t remember what all we took off, but I know we had to do something with the compressor or condenser to remove the alternator. I’m hoping we forgot to plug in a sensor or something simple, but it’s so tight in there I wouldn’t know where to look to see? Any way you could point me in that direction on what to check?

IIRC the sensor is right on top of the drier bottle, so you should be able to see it just by removing the plastic cover forward of the radiator.