[djsamuel]

I had an issue on my 04 PT where the dash lights and interior light (and possibly tail lights) came on when I started the car and would not turn off. I disconnected the battery and waited a few minutes to reset the BCM. That cleared the issue. Shortly after that (a matter of days), I needed to replace the battery. That was about 2 years ago, and no problems since.

 

[ImperialCrown]

The TIPM (totally integrated power module) is the 'intelligent' underhood fuse/relay box. Its controls are mostly solid state and there aren't many serviceable fuses or relays in it.
Measure the left, then right park lamp circuit resistance to ground to narrow down which side is shorting. Should be over 5 ohms.
Any added or aftermarket alarm/remote start system?

B165C-PARK LAMP CONTROL CIRCUIT LOW

For a complete wiring diagram, refer to the Wiring Information.

• When Monitored:
  With the Parklamps activated.
• Set Condition:
  When the Totally Integrated Power Module (TIPM) detects a low condition.

Possible Causes
(L217) PARK LAMP CONTROL CIRCUIT SHORTED TO GROUND
TOTALLY INTEGRATED POWER MODULE (TIPM)