electrical problem.

IH M dist. 12v alt from YT. Light for resister. After 2 months inactivity battery dead (not usual). Recharged and noticed that with Ign off, light was lit. Brighter with Ign on. Finally got it charged and restarted, light went out. Mowed for 2 hours, light out. Blew a shear pin, getting late, put it in shed in case it would not start. pushed in off switch and engine ran for 2 minutes, then petered out and died.Old and Country Lawyer T, any ideas? Thanks in advance, Earl

sounds as though your alternator circuit is not shutting off when your key is off. did you put a diode in the line from the alternator to keep it from back feeding the alternator.

(quoted from post at 13:58:49 11/02/18)
IH M dist. 12v alt from YT. Light for resister. After 2 months inactivity battery dead (not usual). Recharged and noticed that with Ign off, light was lit. Brighter with Ign on. Finally got it charged and restarted, light went out. Mowed for 2 hours, light out. Blew a shear pin, getting late, put it in shed in case it would not start. pushed in off switch and engine ran for 2 minutes, then petered out and died.Old and Country Lawyer T, any ideas? Thanks in advance, Earl

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n attempting to help diagnose the electrical problem, which alternator, where in circuit is light, and which light bulb are all vastly more important than shear pin condition or putting in shed.

The bulb needs to have about 15 to 20 Ohms or more to work. Side marker light is good (not LED) a 10 ohm resister will work as well, or diode with the band end toward the alternator. If the diode trio, or the charging diode bridge has a conducting diode the issue will not go away. The above information assumes the light you are using is in the #1 terminal to the ignition sw side of the coil or ballast resistor. Jim

was charging fine over the last 2 years. just happened. Will take meter to it when I get back. 2 hour ride.

I'm not sure how its wired but IF its a Delco SI 3 wire setup and if there's a small incandescent (NOT LED) bulb in the circuit from a hot voltage source to the small side 1R alternator terminal that should be lit (when ign ON if thats the source) until the alternator starts spinning and producing its own voltage at which time it should go OFF. HOWEVER if it stays lit with ignition OFF it must not be wired as typical where the wire to the bulb is hot ONLY if ignition is on (via feed to the coil). If its wired right and stays lit that means the alternator isn't producing enough to self excite. Are you sure the wire to the small 1R alternator terminal has a resistor or an incandescent lamp or a diode between the source and 1R ??? The Delco 10SI 3 wire alternator needs initial excitation voltage on 1R to get it working and it also needs a method to prevent run on with ignition off which is why a diode or resistor or lamp is in that circuit BUT IT HAS TO BE THERE AND CANT BE TOO MUCH RESISTANCE like an LED.

PS is this even a 3 wire setup or a one wire??? One from YT may be a one wire??? Why light is on with ignition off is a puzzle as in the typical 3 wire the ign has to be on as that's the voltage source. If it stays lit even with ignition off it must not be using the ign switch as the source voltage.

If its a one wire they require a fairly fast RPM before they excite, sometimes people change pully sizes to increase alternator RPM to get them working right.

I dont know how its wired or what type alternator it is so I best stop guessing lol

John T