Hiddenvision:
Ahh So that clears it up a little.So once you get the original module working you can connect your Arduino wires to some points.
Use common grounds for ease.Pin 11 will be ttl level data FROM the PCU on its way to the computer
Pin 12 will be ttl level data TO the PCU (From computer to the controller)
Connect 11 or 12 to serial RX on an arduino to monitor the traffic in each direction.pin 13 will be RS232 level data of Pin 12 (From computer to the controller)
pin 14 will be RS232 level data of Pin 11 (From controller to computer)
Connect 13 or 14 to pin 2 on a 9pin serial port to monitor the traffic in each direction.Remember that you only want to monitor the traffic first, see what the software says, see how the PCU responds.
When you talk about the pins above, do you refer to the connectors on the max232 chip, or the rs232 db9 pins?
Sorry for my newbie-ness 
Thank you so much for helping med out!