F20 wiring

1070BK · Mar 9, 2016

First of all I want to thank everyone for the help I've received from this forum. I'm finally closer to getting this project running. I'm now totally confused with what should be quite easy. How to wire a F20. Here's what I have. Fairbanks Morse type FM 1wire mag; 12v Delco alternator out of a Chevy; Delco 12v starter with a mounted 3 post solenoid. Plan on running everything thru an H/M style push button switch and amp gauge/light switch box. I tried to wire it similar to an M, but that didn't make sense since the starter is different. Looked at a wire diagram for a 350, but that didn't seem to work either. I just don't think this should be so difficult. Its not like there was anything there before to confuse me. Figure I'm missing one simple step. As of right now I have all wires and cables off. Time to start over. Any help would be appreciated.

F-Dean · Mar 9, 2016

Here are my suggestions based on my electric start F-20s.
1. Use a keyed switch to activate the solenoid for safety - take the key out when parked at shows.
2. "Sneak" a grounding wire out the back side of the mag to a one-wire H/M kill switch. Connect this to the condenser in the mag.
3. Place the solenoid in a direct line from the battery to the starter to minimize "Line Loss."

36F30 · Mar 9, 2016

Not sure what you mean by a one wire mag or if thats a typo, on the side of the Fairbanks mag is a grounding tab on a post. If you hook a wire to this and run it to normally open push button switch and then to chassis ground it will ground out the mag and stop the engine. It should not be connected to the "electrical" system in any manner.

1070BK · Mar 9, 2016

Yes, I failed to mention that I do have a separate wire from the mag to a single pole switch but I was failing to ground it. Should I be using a
double pole switch instead?

36F30 · Mar 9, 2016

(quoted from post at 20:14:51 03/09/16) Yes, I failed to mention that I do have a separate wire from the mag to a single pole switch but I was failing to ground it. Should I be using a
double pole switch instead?

The single terminal switch should work if its good and its body is well grounded.

1070BK · Mar 10, 2016

I assume a key switch similar to one on a 560 would work. I think I have the ground wire figured out for the mag. I ran a cable from the battery to the solenoid and then a cable from the solenoid to the push button switch but the switch would get quite warm.

F20 wiring

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