Originally Posted by scottydsntknow
He said he already had it bench checked. Its likely a draw somewhere from a crudded up ground or crossed/chaffed wire or something.
He said the shop checked it when he got a battery, I used to work in one when I was 17, you cant always trust the test was good. In fact most are just a dumb go-no-go box put on the battery. The tests above will verify exactly if its a charging issue or a draining issue. Charging issues can be caused by things other than the alternator.
If both of those tests go OK, then likely something is draining the battery FAST. If something that is draining the battery that fast, I would remove the fuse from the last aftermarket device put in (radio?) and see if the drain stops.
My bet is those tests wont go OK, and then its between the battery to the alternator. Alternator, wires, something else I would need to see the wiring schematic online someplace.
a draw somewhere from a crudded up ground or crossed/chaffed wire or something.
A bad ground could prevent charging, not cause a drain on the battery while its sitting. Same with the cruded up wire, failure to charge rather than a drain while not running. This is likely what you meant but I wanted the electrical theory to be stated correctly while trying to show electrical tests.
A crossed wire with failed insulation could cause a short, shorts that drain fast are going to blow a fuse or burn up the wire. Good time to open the page that shows where the fuse boxes are in the model car this is and check the fuses with the ->- diode symbol on the $3.95 Red Harbor Freight Digital Multimeter (or other one that the OP might have or get get cheap)