EZGO Coil

[virgilward]

Got a new coil for EZGO but terminals aren't marked Positive or Negative so I am assuming it doesn't matter which wire goes where , am I correct in this assumption Thanks

[jeffrun]

yes,its makes a difference,will effect performance of the coil, + is power to coil, - is to ignitor. There should be marks on top of coil adjacent to terminals stamped in the plastic.

[Dave Box]

It is not so much about coil polarity but more because the spark plugs do care which way the electrons are flowing in the high tension circuit. The spark plug has a thermally insulated center electrode (surrounded by ceramic). With engine running the center electrode runs substantially hotter than the exposed end electrode. Design of the ceramic insulator determines how hot the center electrode will run, leading to the designation of hotter or colder spark plugs. As electrons go, they love to jump away from a hot surface and fly toward a colder surface, so it is easier to drive them from hot to cold rather than from cold to hot. End result is a difference of 15 to 30 percent in voltage required to make spark "initially" jump the gap on the plug depending on which way it is going. So the spark plug prefers to see a voltage potential that is negative on the center electrode and positive on the end electrode for the very first hop of the spark. Oddly enough, this has nothing to do with polarity of the vehicle electrical system, but it is influenced by the common connection inside the ignition coil.

If you are still skeptical about all this, there is a quick way to check directly which way the current is flowing in the high tension circuit. Disconnect the spark wire from a spark plug . Hold this HT wire near a grounding point (or near the connector end of a spark plug), and position the tip of a graphite pencil in between. When you crank the engine (no need to start or run) you can observe the resulting spark jump between wire and pencil, and between pencil and ground (or spark plug). A flare (hard to see) toward the plug (or ground) shows correct polarity while a flare toward the coil shows reversed polarity. If the flare goes toward the coil, just switch the primary wires on the coil and make note of the connections for future reference.

Dave

[virgilward]

There is no identification at all on coil Thanks