I disconnected battery and all a/c pressure switches and wiring. Reconnect battery and I fire it up and fans still come on and high head pressure. At this point I am stumped!
I start thinking, both relays can't be stuck on. Then I try to get compressor clutch going by jumping the connector at the drier. PCM see a/c request and clutch engage, but no compressor clutch engagement. Then it hits me, must be a wiring problem to high pressure switch.
I follow wiring and find a cluster of wires rubbing the belt. Not good I think. I look closer and I see metal and melted wire housing. WTF. One wire is totally broken, a black one. That must be the problem. I wrap the other wires as they were so close to being destroyed and repair broken wire. I wrap with electrical tape and place back in what is left of the plastic housing. I position the wiring harness so it is not going to be struck by the belt or anything hot.
I fire up and no fans. Check PCM and head pressure is normal. Case Closed!
So apparently by default, the PCM will activate the fans when a signal is lost from the high pressure switch.