2003 Dakota 3.9 SLT 4x4. While driving battery light comes on & engine runs till battery dies. Batt & alt checked out as good. Took to dealer & they ran electrical test & couldn't find any parasitic drains. Put full charge on batt & ran for approx 1 1/2 hrs till battery is drained. I unplugged connections on PCM & sprayed with contact cleaner & applied dialectic grease & reconnected. Drove for 2wks before battery light came on again. Is the PCM bad or is it another culprit. Thanks for any advice you could possibly send my way!!!