A test light is not very accurate way to check for a draw on this system because of the modules or computers on this vehicle. It has to be able to have voltage and current draw to go into the sleep mode which takes about 30 minutes.
You will need an voltmeter that measures amps to do this. First open drivers door then take a screw driver and trip the latch in the side of the door so the interior lights go off. Unhook the neg cable.Take a jumper wire and hook in between the neg cable and battery. This is to keep from blowing the fuse in your meter until modules go to sleep.
Now hook you amp meter in between the neg cable and battery and walk away for about 35 minutes. Then come back and remove the jumper wire and read your meter. It should read 0.05 amps or less. Now if reading more than this start unhooking fuses until it goes away.
Now on some when you unhook the fuse and plug it back in the amps may jump up but if you do not activate anything in the vehicle it should drop right back down in a couple of minutes. You will have to take your time and be patient it can be time consuming but this will lead you to your drain on the system.
Here is a pic of the meter hook up
No you can have the battery tested.
If you have a draw on the system it could be anything really including the alternator,which I forgot to mention when doing your test also unhook the 3 wire connector on the alternator to make sure it is not the draw along with pulling fuses. You will have to first isolate the circuit or system before you can determine what is causing the draw.
No because as I explained earlier the test light may not be letting current flow so the modules can go into sleep mode,plus you would have to wait about 30 minutes after unhooking before you would have an accurate reading because the modules are still awake,waiting for a command.
Think of it like your home computer. They have to go into screen saver before you can test it but it takes 30 minutes on these.
instrument panel fuse panel
Why do you ask?
That one feeds the fuse panel under the dash. Now you will have to go to that one and start pulling fuses to see which one takes it away. Make sure you trip the latch in the door and wait for the screen saver before starting.
Like I said it will be time consuming but once you get it localized it will be easier.