I was wiring my mags today on a brand new IO 360 M1b engine from vans. Well when I finished both mags were always grounded, I figured the shield must be touching the center conductor, but when I checked with the voltmeter the wire is good. Now this has me really confused, with all the wires disconected from both mags they are both still grounded??? I tested this by using my voltmeter from the p-lead to the firewall. can someone please tell me what I'm missing, I can't have 2 bad mags on a brand new engine can I?