Alternator problems

[Dano41]

Hi,the alernator on a Massy 35 I recently bought wasn't working I have found out that the problem was the warning light.I bye passed the warning light from the battery plus through an ordinary car bulb to the alternator and it works perfect.I have read of some people putting a resistor on the warning light.The resistance in the warning light is 23 ohms and the car bulb is 1.5 ohms.Can anyone one help with this?

 

[Jim.ME]

(quoted from post at 13:00:04 10/15/20) Hi,the alernator on a Massy 35 I recently bought wasn't working I have found out that the problem was the warning light.I bye passed the warning light from the battery plus through an ordinary car bulb to the alternator and it works perfect.I have read of some people putting a resistor on the warning light.The resistance in the warning light is 23 ohms and the car bulb is 1.5 ohms.Can anyone one help with this?

LEDs don't work, a common incandescent indicator light should work, I have several on JD units, automotive bulb #1895, 3.8 watt, 14 volt miniature bulb is what those use. (I think that calculates to about 51 ohms.) Is your indicator light in the Battery positive wire or is it in a switched wire coming from the ignition switch?

Just curious, what is your general location?

 

[Dano41]

Switched wire from ignition.Donegal Ireland.

 

[Jim.ME]

(quoted from post at 15:37:02 10/15/20) Switched wire from ignition.Donegal Ireland.

Engine off. With the tractor's indicator light hooked up as original, do you get battery voltage, or very close to that, at the terminal of the alternator via the indicator wire?

Some have used a 10 ohm resistor rated at 2 watts or higher, without an indicator light, in the switched wire. The resistor and an LED might work, I haven't tried that.

A 50 volt, 1 amp diode will work. I have a couple tractors converted to 12 volts with Delco alternators, that use ammeters, no indicator lights, with diodes in the switched wire.

 

[Dano41]

Engine off and key off I don't get battery voltage key on engine off I do.Sent away for replacement incandesent bulb.Could I have connected a diode between the two lamp pins and got the light to go off and the alternator charging?