replacing a ammeter with a voltmeter

noodles · Jul 11, 2018

I have a mf-35 perkins diesel .would like to replace a broken ammeter with a voltmeter what is the wiring hookup? thanks Michael

grayrider · Jul 11, 2018

Run a wire from your positive post on battery to positive side
of volt meter and then a wire from negative side of volt meter
to good ground

Bob M · Jul 11, 2018

Easy!

1 - Disconnect the wires from both posts on the old ammeter. Now connect ALL the ammeter wires together. Be sure you make a solid connection - a small bolt and nut thru all the terminals then thoroughly tightened, then taped with several layers is recommended)

2 - Using #16 or #14 wire connect the hot (+) terminal of the voltmeter to the ignition switch "I", "IGN" or "ACC" terminal. Connect the voltmeter "-" terminal to a solid ground. (Assumes your 35 system is negative ground. If positive ground simply reverse the connections at the voltmeter).

Adirondack case guy · Jul 11, 2018

That leaves the volt meter hooked all the time, and a constant drain on battery. Need to hook the volt meter through ignition switch to break circuit when not in use.
Loren

JoeM(GA) · Jul 11, 2018

your starter switch if like most older Massey diesels only has two wires going to it, there is no "switched" hot on it that stays hot after it cranks.

If yours is that way you'll have to tie the hot of the gauge to to the pressure switch you'll find on the back of the oil pressure gauge. You'll have to check with a test light or meter to find which side is only hot when engine is running and oil pressure has reached enough for the switch to close.

replacing a ammeter with a voltmeter

noodles

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grayrider

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Bob M

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Adirondack case guy

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JoeM(GA)

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