by geeves » Fri Nov 11, 2016 2:53 pm
Do the same test directly across both the battery posts and the outside of the battery terminals.
My money is on either a flat battery or a white oxide on the inside surfaces of the battery terminals. If you have the lead type batery clamps they get an oxide on them which is white hard to remove and quite a good insulator
Sanding your knuckles before starting work can help. That way you cant skin them