Battery Run Down

99 Intrigue 3.5, 212,000 with car off dash lights, gauges stay on, occasional tail and DTR lights on, air bag light flashes on dash and warning light sounds. Things may sometimes go off or change while push on brake pedal. Replaced ignition switch, but things are pretty much the same. Had codes read - Code U1016 Loss of Power Control Module. End result is overnight the battery is run down. I did not do a relearn when replaced ignition switch. Car starts and runs fine. Any ideas on what my problems is? Also I had engine replaced with used engine about 6 months ago due to knock of death. No problems after engine replacment, the battery run down problem started about two weeks ago. One more thing, Thanks littlehove for the ignition switch instructions

Power contol module sounds like a BCM problem......need to go to someone who has a scan tool capable of reading, "P", "B", and "U" codes and also read data from the BCM......