04 ac clutch not kicking in

[Cntrysthbst]

This started happening when I pressure washed the engine compartment. Did not disconnect the battery, but did let it sit for a day. Probably not a good idea in future, was careful in what I washed. Anyways the clutch will not kick in. The relay for AC and fuse are fine. No leaks. I disconnected the ac presure switch and fans came on high and then turned off after a couple minutes, turning engine off and restarting the fans did not come back on with plug off of AC pressure switch, plugging it back in and fans stay off till engine gets warmer. Climate control is set to LO on drivers, passengers, and rear as well. Nothing happens when I push AC button. Everything is in good shape, new belt, alt., battery, just about all is newer including the PCM. I hooked up OBD2 scan tool and have no codes. All the plugs are dry and clean. Drives great, not other problems except clutch not kicking in. Need help on what I caused to go wrong on this, thanks

Found some codes on dash...not through using scan tool.

1. P0645 Air Conditioning (A/C) Clutch Relay Control Circuit
2. P1598 Air Conditioning (A/C) Pressure Sensor Volts to High

Sounding like sensor is problem, can I replace it without discharging the system?

[Cntrysthbst]

We reset the BCM. Clutch is working now but after a couple minutes ac fluid and air come out at really high pressure on the bottom of the ac compressor. Looks like where it is coming from is for an overcharged system to protect the compressor from damage. It is on the bottom opposite the clutch side facing down. And we didnt see or hear the fans kick in after coming home and checking, engine was warm but it has been cold here so no clue on if they should come on or not.

[Cntrysthbst]

This link is awesome, great job and very well explained! This is the problem with ours. Link is the info,

http://www.autotechonwheels.com/smjun08.htm

Hope this helps...