From your description and now with the photo of the red wire under the seat, this could be... your problem right here.
Two bare wires, grounding against the bolt on the seat base maybe? This needs to be addressed first imo.
IF... this is for the seat height adjustment switch under the drivers seat, or it might be something else?
Something the previous owner has patched into?
IF these wires are under the passenger seat, could be the amp for the sound system or the previous owner might
have tapped into this hot lead, for something else unknown to you when you purchased the car?
Trace these wires if you can, to see where the go to? Might give us a clue to what
other problems might be involved here for you to look for?
New battery installed, alternator is ok, runs and charges ok while driving, but when sitting still it drains your battery, grounding problem?
I would check other grounding points for any corrosion within the car. Check the fuses in both locations just in case something in there is blown?
Not charging when sitting still is the big question here? Robo & JohnWR & TomatoSoup are the guys to go to when you have electrical problems here on the forum. IF these wires are the problem, and you fix those, and then it still does it again, it is a process of elimination here.
Electrical gremlins are sometimes hard to find in any car.
Fix these two wires first, then see if your battery goes dead again? Get back to us with your results and hopefully
our guys can narrow down what or where else for you to look for a drain to your electric system.
Luck with it.
Last edited by LAC Sky; 06-12-2019 at 06:05 AM.