International cub lo boy no voltage

I have a smaller cub lo boy with 12v battery ignition with distributor and coil.
What I thought was bad connections turned into something else. I can start the tractor by hotwiring directly from the battery to the coil. Tractor stays running after i remove the wire. Will not start any other way. No voltage to the key switch. I checked both the wire coming from the regulator and going to the coil with ohm metrr. Both fine. Im at a loss why i have no voltage to my 2 position key. I need some help.
 
Check the switch itself for continuity, the contacts may worn if its an old switch. If its a new could be bad right out of
the box.
 
(quoted from post at 10:30:09 09/15/20) Check the switch itself for continuity, the contacts may worn if its an old switch. If its a new could be bad right out of
the box.
riginal switch. I believe the switch works, but no power to the switch.
 
What sometimes happens is a "voltage droop" at the coil when the starter is turning and drawing a lot of amperage. I am not sure exactly where the coil normally gets its current from on your tractor, but it seems like by jumpering it the way you describe, you may be making sure it gets a full 12 volts (or as close to it as possible) when the starter is turning. Then, once the tractor is running, the coil gets the full voltage as the starter isn't consuming any current. Also, once running, the generator or alternator (whichever you have), helps raise system voltage back up to 12--usually a little more, maybe 12.5 or even 13--again, helping the coil get the full voltage it needs to give you a hot spark.

If this is a 12 volt w/alternator, I suspect a bad connection between the positive battery terminal, ammeter and the coil somewhere, or an old/tired battery, or even something wrong with the starter causing it to draw more current than normal. It could even be fouled plugs that don't spark with the weaker starting spark, but then spark well enough to run once the starter is disengaged and the generator/alternator is up and running and the system is at full voltage. See if you can get a voltage reading at the coil connection (no jumper wire) while an assistant presses the starter button/lever. Compare this to the battery voltage just sitting there, with the starter engaged, and again when running.

I'll say this is unusual for a 12 volt system. 6V systems are more prone to the coil cutting out when the starter is engaged, but it is possible for a 12V system to do this too.
 
If the wire to the Key switch comes from the amp meter, and the wire from the amp meter to the starter relay (solenoid) is bad, the generator will provide
electricity to the key through the charging circuit. The lights would then work while it was running. Jim
 
(quoted from post at 12:01:35 09/15/20) If the wire to the Key switch comes from the amp meter, and the wire from the amp meter to the starter relay (solenoid) is bad, the generator will provide
electricity to the key through the charging circuit. The lights would then work while it was running. Jim
I should also mention that when this all started, it just died on me while mowing. I put new plug wires on, new points and condenser and rotor. If i put a jumper from the battery to the hot side of the switch and turn the key, i get full voltage at the coil.
Could i have a dead short in the ammeter or a faulty regulator? Looks like power fot the switch comes back from the regulator. Also i could wiggle wires and it would stop firing.
 
If it dies when wiggling wires, then it seems you have some sort of intermittent ground or fault. The new plugs, cap, rotor and wires certainly didn't hurt, but likely were not the cause. It sounds like you have a generator. It is possible that the circuit is grounding through the generator and regulator. It may be helpful to try it with those disconnected for a little while to see if that solves the problem. That would at least rule that in or out.
 
(quoted from post at 16:49:21 09/15/20) Kinda confused here, youre using both the original switch and a key switch? If so, how do you have it wired?
Sorry for the confusion. Just a on/off key switch.
Should be a hot wire on one side of the switch and the other going to the coil, but I have no voltage going to the hot side of the key switch.
 
The ignition switch (key or push pull) needs battery power to turn on the ignition coil. Normally the key is attached to the amp gauge, negative side (load).
to get there, the power flows through the amp gauge. The supply to the amp gauge comes from the starter solenoid (relay) and is on the same big terminal as the
battery cable. Tracing power with a light type tester with the alligator clamp attached to ground will find the disconnect/open wire or bad connection. Jim
 
(quoted from post at 12:44:47 09/16/20) The ignition switch (key or push pull) needs battery power to turn on the ignition coil. Normally the key is attached to the amp gauge, negative side (load).
to get there, the power flows through the amp gauge. The supply to the amp gauge comes from the starter solenoid (relay) and is on the same big terminal as the
battery cable. Tracing power with a light type tester with the alligator clamp attached to ground will find the disconnect/open wire or bad connection. Jim
believe Ive found the problem. I believe my amp guage is dead. If i jump across the guage, I have voltage where i need it.
 
Inside the gauge is a calibrated conductor with a very small but known resistance. This is called a shunt. The gauge needle reads the much smaller amps flowing
through the meter coils. If the shunt fails the gauge is no longer conducting, the meter windings fail, and it goes dead. Jim
 
(quoted from post at 09:34:37 09/18/20) Inside the gauge is a calibrated conductor with a very small but known resistance. This is called a shunt. The gauge needle reads the much smaller amps flowing
through the meter coils. If the shunt fails the gauge is no longer conducting, the meter windings fail, and it goes dead. Jim
Jim, I'm sure this is whats happened. New amp gauge on the way.
 

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