'01 9400 AC issues

Check to see if you have an APADs module. You didn't say what year your truck is, but they are typically mounted on the left side of the firewall near the coolant reservoir. It should have a green LED on. If it has a red LED on you can try to reset it by cycling the key off and on 4 times in 4 seconds. Other than that there is many things to cause no power to the compressor. I highly recommend an International dealer because they will know your truck the best and have the proper wire diagrams. A general A/C shop may waste a lot of time and also your money from scratching their heads.

 

That should have absolutely nothing to do with the a/c. A new harness would never been needed. If you have broken wire you re-run that wire only, not a new harness.

 

How can the compressor run backwards? No power to comp is probably low freon, the low pressure switch will cut off power to power to compressor

 

If you don't have APADS. Check top two circuit breakers on left side to see if they are tripped. Then check second relay down on left and then there is one more relay on bottom row. I think it is the sixth over. It will be on fuse panel. Check those and then stop back by.

 

That is after you make sure you have proper charge.

 

I had a 9400 with a 12.7, nothing any good a/c shop can't repair.

 

First off, a compressor cannot run backwards. It's belt driven. The compressor will NOT turn on if there isn't enough refrigerant in the system. My guess is that they either broke a hose or flexed one enough for all the refrigerant to escape when they replaced your radiator. They had to either move your condenser or take it out. That would have released all your gas.

Any shop can put a gauge on there and measure the pressure. That would be your first step. You can also buy a few cans of gas and see if the clutch engages on the compressor. Like I said, the clutch will NOT engage unless there is enough gas in the system