Farmall c alternator wiring

farmersam01 · May 4, 2015

I'm in the process of converting my c to 12 volt. I have the lights fixed, the alternator mounted, the battery installed, now I just need to hook the alterntor up. My question is, according to this diagram it says I need a diode or a light? What's that for? Will the charging system work properly without it? I don't think I want to add that and I don't know what it does without it. If anyone can help I'd greatly appreciate it. Thank you!!

Jon Hagen · May 4, 2015

If your using a 3 wire 10 SI series Delco alternator, you need power from the ignition switch to the alternators #1 terminal to start it charging. If you do not have either a diode or indicator light inline in that wire, the alternator will backfeed power to the ignition coil and keep the engine running even with the ignition switch turned off. (This is with a battery ignition, not a magneto.)
I perfer the warning lamp for two reasons,! it serves as a charge indicator , and 2 it restricts power to the alternator to less than 1/4 amp, while the diode will flow as much as 3 amps to the alternator, overloading the ignition circuit, causing possible weak spark.

Bob M · May 4, 2015

Ditto Jon's comments. Further, I prefer a light as it will warn instantly should either the fan or alternator belt break.

Steve@Advance · May 4, 2015

"Will the charging system work properly without it?"

Answer: No, it is necessary for the alternator to charge, it is also necessary to prevent feedback to the ignition coil.

shunkfarm · May 4, 2015

You can buy one or convert yours to a one wire charge. You only need a wire to the battery then. Very clean!
J

Farmall c alternator wiring

farmersam01

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Jon Hagen

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Bob M

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Steve@Advance

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shunkfarm

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