RE: Current Draw
Your basic setup is fine, cable (either one) removed from the battery then
put the test instrument between the cable and the battery to complete the
circuit.
Now go back to the multimeter.  You will most likely find a setting that
says DC 10 amps (or maybe 20 on some metes).  Set the meter to that setting
and put it between the battery and the cable, just like you did the light
bulb.  You should get a reading.  If small, under one amp (all numbers to
the right of the decimal point) then look for a lower setting under DC Amps
and to to that.
Ideally you should se no more than 50-100 mv.  More than that especially 1
amp or more means that is a draw downstream.
And you might not have pulled all the fuses, there are some buried above the
fuse block.  And don't forget the fuses for the camper equipment (assuming a
Westy).