Is the rubber cap really necessary? There are fully insulated spade connectors, both male and female, available at any good auto parts store. Maybe use a piece of shrink tube about an inch long just behind the connectors to keep the wires together.
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!