Disconnect the alternator...a fused out diode can have the power flowing back down to ground.
See if that helps limit the draining current.
I still cannot work out from your picture how you are measuring current in series with the battery...best to totally remove the large battery clamp from the battery...connect the red lead from your meter to this clamp and the black meter lead to the red terminal on the battery. This way you will definitely get all current flow, including the flow through the alternator.
I see from your first picture that the right-most plug position on your meter will let you measure milli-amps provided you turn the rotary switch to the correct position...the plug position you are using is for up to 10 amps probably.
Last edited by Billwill; 01-14-2013 at 01:17 AM.