Originally Posted By jlatessa
I've seen instances like this where both heads have connecting grounds, why would this be needed?

Thanks, Joe


Spark plugs have to be grounded to fire. Ground on both heads prevents any issues with the path that voltage follows passing through the assembly to a single ground point. Either with the spark plug function, damage to engine components or RF interfering with electronics.

Is it redundant? Maybe, but the conversation is about assembling a trouble-free electrical system.

If the results don't match the theory, change the theory.