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Alternator Exciter Wire Gauge

Practical Motorsport Wiring - Professional Level

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I've been building my Honda K20 harnesses using primarily 20AWG Tefzel wire, but want to step down to 22AWG where I can. I plan to run 22AWG everywhere except keep the ignition coils at 20AWG. I'm unsure if it will be safe to do so with the alternator wire. Does anyone know how much current it will draw?

Field current goes up as output goes up, so it's not a one sized fits all question. Generally for most automotive sized alternators they A. draw ~5 amps at ~100 amps of output and B. many/most/all pull from the diode trio as it feeds back into the field.

So yes, you'll be a ok with 22 awg as the field supply from outside the alternator is generally only needed when its not spinning/to get the field excited.


Thanks for the explanation and confirming.

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