Sorry I haven't commented. Been out of town all week and I'm on dial up right now. Should be back home in a few days.
Personally, if the WP is good then the car needs to be scanned by someone with a tuner who can see what's going on in the PCM. The fans not turning on has me concerned. Have you tried swapping around relays? I don't know the GP's wiring off hand, but maybe one of the relays for the fans is bad (low fan) and the high relay turns on both fans. This would explain why the fans come on with the A/C but not normally.
Hope that helps.
