Adding Push Button Start To a B
I had decided some time ago that I wanted to add push button start capability to my 1942 AC-B. It's not really that hard to do. I had already converted the old 6v positive ground generator system over to a 12v negative ground alternator system, so I selected a 12v, negative ground starter solenoid as the key component. The solenoid is NAPA Echlin #ST82. For the push button itself, I chose a normally open, momentary contact push button switch. Here's where I mounted the starter solenoid:
You'll also notice that I have changed from the standard braided ground strap that attaches to the steering column post to regular cable attached directly to the starter locking stud. I think this arrangement gives me a little better ground to the starter with less chances for a poor connection. I'm also using nice flexible welding cable with replaceable end fittings for all the high amperage starter wiring. That makes it extremely easy to do your own custom length battery cables.
The push button switch is installed in my modified instrument panel as seen here:
The wiring of the switch and solenoid is shown here:
Notice that I installed the alternator output to the same solenoid terminal as the battery positive cable. That's because I have replaced the standard ammeter with a voltmeter as shown in my instrument panel above. If I still had an ammeter, the ammeter would be installed in this circuit between the solenoid and the alternator output.
You'll have to find a way to force the contacts in the original manual starter switch to stay closed at all times. I took mine apart and modified it to accomplish that. I understand that NAPA (Echlin) has a kit to do it but I don't have the details.