I have a friend installing power windows in his 69 coupe. There's a wire with a grommet that comes from the inside of the car, through the firewall & goes to the circuit breaker. I went though the AIMs book but couldn't come up with a definitive answer as to where that hole needs to be. Even the chart doesn't show that hole. Power top should have the same hole. It should be 1/2". Can anybody help please & tell me the location of that hole? Thank you, Joe