574 ignition part

Mike Van · Dec 10, 2019

A few days ago my 574 gas engine wouldn't turn off with the switch - Looking aroound under the hood for a problem, I found whats called a diode, hot enough to melt the plastic on it. Pulling the connector apart, tractor shut off. Where to find the part # for this diode?

Bob · Dec 10, 2019

(quoted from post at 13:23:36 12/10/19) A few days ago my 574 gas engine wouldn't turn off with the switch - Looking aroound under the hood for a problem, I found whats called a diode, hot enough to melt the plastic on it. Pulling the connector apart, tractor shut off. Where to find the part # for this diode?

Sounds like it's an alternator conversion using a diode in the alternator "excite" circuit.

I use 1N5408 diodes for this purpose, their voltage and current ratings are "overkill" for this use, yet they are CHEAP.

If you GOOGLE the # you will find an almost unlimited amount of sources.

One seller has them 10 for $1.89 on ebay!

Others on here will argue to use a much less current and voltage rated diode, yet they will not be anymore than a few pennies cheaper, at the most.

Once you get a new diode, note the while band at one end (cathode).

That end gets wired to the alternator's #1 (excite) terminal.

Bob M · Dec 10, 2019

1N4004 (also 4005, 4006, 4007, etc) work too.

Last 1N4004 I purchased was 29 cents(!)

caterpillar guy · Dec 10, 2019

Should have already been equipped with an alternator from factory. Ours was, though it was a diesel.

dwag · Dec 11, 2019

Part# 548239R2

574 ignition part

Mike Van

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Bob

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Bob M

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caterpillar guy

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dwag

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