Can a faulty Combination switch cause a parasitic battery draw

I have a 2001 buick park ave ultra, and for the past year I have been dealing
with the the issue of a battery draw.Things I have found so far the draw is
coming from my Batt 1 60A fuse circuit with the key off.My left turn signal
doesn't work all the time some days it does others it doesn't I have change
the relay out already no change, but there is no effect on the right side nor
the hazards and this is even before I changed the relay out .No interior lights
stay on which tells me my BCM is working no glove box,trunk light ,radio,nor
lighter has power after power down I even left the lights on to be completely
sure.One thing I did notice is that my frt passenger door when opened
doesn't turn on the interior lights, and also my voltage gauge fluctuates allot
with the car running/driving and me monitoring it.Any help