The wiring diagram shows two red wires coming off the + batt terminal. The big one goes directly to the starter. The 2nd one goes to the Mega Fuse (Right side of battery juntion block). After the mega fuse, an orange/blue and yellow/wht wire goes to the alternator.
As for battery drain, here's how it's diagnosed. You will need either a low amp clamp meter, or a digital multimeter with an amps featuer. The clamp meter is easiest. You clamp the meter onto the negative battery cable and wait for 3-5 minutes after the car has been shut down. At that point, you should see a significant drop in millamps due to computer shutdown. After shutdown, you should see no more than 50 milliamps. That power usually goes to the clock in your radio and any keep alive memory in the computer. If you see more than 50 milliamps, you've got something that's not shutting down. To find out what that something is, remove 1 fuse at a time until you see a drop in current draw. You should also pull each relay to check for the same drop. Most of the time, an intermittant problem like this is caused by a gremlin relay.
Another way to check is to attach the low amp probe and smack each relay with the handle of a screwdriver. If the current drops, you've found the bad relay.
If you have to use the digital multi-meter, you'll have to hook it in series with the negative battery cable.
Retired ASE Master/L-1 Technician.