Dwell / Tachometer Question

Posted by JD in KC On 2008/12/20 13:25:52

I'm hoping to pick up a dwell/tach meter off of eBay or Craigslist. My question is, do I need to get one that is specifically for 6volt positive ground, or is voltage/ground even relevant to the pre-70's meters? Most of what I've seen were 'found in Granpa's garage' and don't have the manual with them. In one case the manual was there, but supposedly made no mention of required voltage/grounding. Any help/information is appreciated as always.