Zener diode? Zener diode? That sounds suspiciously like a flux capacitor. Why do I have the feeling that when I go into Radio Shack and ask them for the part they'll all fall on the floor laughing at me? I envision one of them attaching a 'KICK ME' sign on my back as I turn to leave with my head hung low. LOL.
Thanks for the info Anders. It'll be a few more days (at least) until I get around to the install. Maybe I should get one for each of our vehicles running MSD boxes. So, you think we'd be able to put a battery charger on the cars without risking damage to these electronic controllers then, right?