'd carry on w/ the battery test - pulling fuses showed the accessory circuits are ok, but the battery + also connects to the starter, the ammeter, and voltage regulator [and generator thru the regulator] - pull the big wire off the BATT terminal of the regulator first, which should indicate if the problem is in the charging circuit, if not then it's under the dash
turn switch could affect rear lights, but if you have some function back there, and the front blinkers work, that's not too likely to be causing the battery drain - need to test from the beginning to see where you loose the power to the tail - brakes get their power from the light switch usually, go thru the pedal controlled switch, then to the blinkers where it's a straight thru thing if the blinker's not on - tail lights go from the headlight switch straight to the tail lights, not involved w/ blinkers
Bill