12 volt conversion with alternator

mwilke · May 25, 2014

I bought a Farmall B with an alternator/12 volt conversion. How can I tell if the alternator is charging? I hooked an electric sprayer pump to the battery with tractor running and it seemed to drain the battery after about an hour or so. Thanks for any help.

rvirgil_KS · May 25, 2014

If it has an ammeter, it should swing to the + side when it charges, - side if discharging

Check voltage across battery with engine off. Should be about 12.5 volts. Start engine and battery voltage should go to 13.5 to 14 range

If it has an "idiot light", the light should come on when switch is turned on, the light should turn off when engine runs and alternator starts to charge.

mwilke · May 25, 2014

Thanks for the reply. It has neither an ammeter or an idiot light. I will check the voltage. I suppose I could install an ammeter.

Steve@Advance · May 25, 2014

So, does the alternator keep the battery up when you're not using the sprayer? Any idea how many amps the sprayer pulls?

If the sprayer pulls more amps than the alternator can make, a higher output alternator will be needed.

If the alternator keeps the battery up without the sprayer, and the sprayer has minimal amp draw, there could be a problem with the alternator diodes, possibly the belt is loose, or the belt and pulley are mismatched and slipping.

Might look at the wiring also, be sure the alternator is wired properly and a minimum 10ga wire is used for the output.

If you're looking to add a gauge, a volt meter would be much easier to install. An ampmeter requires running heavy (10ga) wire from the alternator, to the gauge, back to the battery. A volt meter only needs a small wire from the ignition switch.

12 volt conversion with alternator

mwilke

Member

rvirgil_KS

Well-known Member

mwilke

Member

Steve@Advance

Well-known Member

Similar threads