I know this is an old post, but I am learning so much from "oldie but goodie" posts! I do not know whether this is the appropriate place to post this, but I've seen while reading about our car that the battery can wreak havoc if not working properly. So here's an idea somebody might benefit from when searching within the forum.

TRUTH: PRESERVING A BATTERY IN MINT CONDITION/FULLY CHARGED WILL PREVENT THE GREMLINS FROM ATTACKING THE CAR ELECTRONICS.

That's why I decided to install this inexpensive voltage/temp/capacity meter on top of the battery, so I can have "accurate" readings at will. It stays in there all the time. Can be turned on and off, so I guess no battery drainage.

Car off reading!

Car on reading!

FYI:

• Do not worry about the battery plugs. That yellowish slime is not rust, it is some sticky plug protector!
• Please notice the TWO wires on the negative plug. One is the original to the body and the one on the left is a new grounding to the engine (just playing it safe, haven't checked the OEM engine to body grounding cable underneath the car (driver's side).

Hope this info helps or contributes to better and more professional ideas. Thanks for all the thorough posting across this forum.

Havagoodday!