[GB SISSON]

I think some of the confusion comes from the fact that many starter solenoids in common use require a 'hot' connection to the small post to get the solenoid to do it's click and energize the starter. I have a drawer with maybe 8 solenoids in it. I'd say half of them work by getting juice from a hot wire through a normal 'wire in, wire out' switch. The other half are from flatheads and those odd solenoids do their trick by grounding out the small terminal. Flathead= ground the terminal, conventional= hot up the terminal. Many years ago I wired up one of my trucks with the wrong type of solenoid so I just ran a conventional momentary 12v switch and 12v to the battery. Worked great, but always confused me when troubleshooting, so found a correct solenoid at swap meet and went back.