Those rubber grommets are only shock mounts- - - -the regulator housing still needs to be grounded, usually with a wire running back to the generator housing so it doesn't have to depend on body/chassis/engine ground straps.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!