Fuse and Light Switch on Super C with Alternator

Bookman · Jun 25, 2018

I have been rewiring and putting in new gauges my dad's 1952 Super C. It has been converted to an alternator.

I am down to the fuse (which had been disconnected) and the light switch (and the lights had been disconnect too)>

The fuse has two wires coming out of it. One goes to the light switch. The other wire has been cut but it looks like it goes to the ignition switch but I am not sure which side. Does anyone have a better wiring diagram or picture of the wires for the light switch, fuse, etc., than what is in the parts book? Thanks in advance.

Janicholson · Jun 25, 2018

The second terminal connects directly to the amp meter load side (the side connected to the ignition switch input) This allows the lights to be
operated without the ignition turned on. Jim

Bookman · Jun 25, 2018

Jim, Thanks much. As I recall, the fuse just protects the lights. I learned a couple of years ago that on my John Deere 420 crawler that when the fuse goes, the entire crawler shuts down. Took my awhile to figure that out since I was used to the Farmall wiring arrangement. Thanks again.

BarnyardEngineering · Jun 26, 2018

I believe OEM the fuse wire would have been connected to the "hot" side of the ignition switch, so the lights could be operated with the ignition switch off.

However, it makes more sense to connect to the load side of the ammeter as Jim indicates above. Wimpy tab connector vs. heavy stud... It's a no-brainer, and how I wire all my tractors.

Jim Becker · Jun 26, 2018

Electrically there is a difference between the hot side of the ignition switch and the load side of the ammeter. The ignition switch is (or was originally) powered from the L terminal of the voltage regulator. Thus, the current draw of the lights doesn't pass through the regulated part of the regulator. This way, the regulator is regulating battery charging not limiting total electrical output. In some situations, the battery may not get adequately recharged.

I hope I got this right. Charging system behavior can be obscure.

Bookman · Jun 26, 2018

Jim, Thanks, Larry

Jim Becker · Jun 26, 2018

I wasn't thinking about the alternator conversion when I made my previous post. My comment applied to the original charging system. After an alternator conversion, there is no L terminal and my comment is meaningless.

Fuse and Light Switch on Super C with Alternator

Bookman

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Janicholson

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Bookman

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BarnyardEngineering

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Jim Becker

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Bookman

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Jim Becker

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