Drove it 100 miles to home - ran great.
First up was the interior - we've done ok so far there.
And then the battery was dead. Hmmmm.
Replaced it. Died right quick. Double Hmmmm.
Disconnected a few optional wiring items (previous owner crup).
Disconnected the battery and plugged the battery in to a charger.
Say WHAT ? The lights still come on, faintly, with the battery removed!!!
Help!

 

There should be two batteries. apparently, the one you did not replace is bad and draining your new one.

 

Found the second one on the side frame under the seating area.
And its deader than a doornail.
BUT
NAPA 16 months - Freebie!!