Re: Problem with charging battery

Posted by HH56 On 2016/10/9 11:34:33

If the coil is hooked up "backward" the spark will be slightly less efficient. No other damage or any outward signs will be noticeable. As long as the + and - is properly connected a 55 or 56 coil will work with either battery polarity.

Having said that, If anyone has an old Delco catalog that lists specs it would be interesting to know what the catalog says the differences are between a 1115084 and a 1115095 coil.

As to performance, the easiest path for a spark to jump is from a small hot surface where electrons are concentrated to a colder surface. In a conventional plug a single center electrode is the hottest and smallest surface and the place where excited electrons will be most plentiful. The center electrode may also be made of or coated with a material having even greater ability to produce electrons. It is much easier for the electrons to make the jump from center to the cooler side electrodes.

With a properly oriented coil that is what will happen but if the polarity is reversed, the spark will need to jump from the grounded relatively large surface of the side electrode which is colder and has fewer excited electrons. The spark will be weaker and in a car with a marginal ignition system or plugs the extra work may be too much. Plugs could misfire or have a very weak spark.