Might have determined my Super C electrical problem

I bought a voltage meter so I was busy checking my tractors electrical system this afternoon.

This is the first time I have ever used a voltage meter on a vehicle of any kind, so I hope I did it correctly.

It is my understanding that the negative terminal of the battery is ground and the positive side of the battery is what flows to the starter and distributor coil.

First things first, I tested my battery voltage. I got 12.0 volts for the battery.

Next, I left the negative end of the voltage meter connected to the negative terminal of the battery, and used the positive wire of the voltage meter to check other parts of the tractor. First I checked the wire that I presume goes to the starting motor. That is the first picture I posted. That also read 12.0 volts.

Second, I checked what I guessed is the distributor coil wire. I traced the wire from the distributor coil back to the battery, so I think that is the input for the distributor coil. In the second picture, I circled what I checked next. There was a small section of exposed wire right before it connected to the distributor coil, so I checked there. That showed only 200 millivolts, 0.2 volts. I used the starter to turn over the engine while I checked the voltage.

What next? Thank you very much!

John

A full battery should be close to to
12.6-13 volts. If at only 12 volts and
then you crank, it might be dropping down
to low to give you enough for spark.

What do you get when actually cranking it
with meter ends on the terminals of the
battery?

12 volts is a discharged battery you need to charge it. A battery should read 12.5 plus volts to be charged and 12.5 if a tad bit low. With it running if the charging system is working you should get 13-14 volts if the charging system is working

The smaller wire (forming a Q out of your green circle) should go to the amp gauge only. It should be the only
thing hooked to one side of the amp gauge. The coil has a resistor on top of it. I believe it also has written on
it "for use with a external resistor". The wire from the ignition "push pull" switch should attach to one side of
this resistor, and the other side of the resistor should attach to the positive side of the coil. The other coil
terminal (-) should be connected to the distributor. If these are reversed, change them. the battery needs to be
at 12.6 volts to start it. If it starts with a charged battery let us know. Jim

Make sure your points are open and check the wire at the distributor with the switch on. If you do not have power there the coil is open/bad or condenser is shorted out. If you then remove the condenser wire and have power at the distributor the condenser is bad. Those are my first checks with a full charged battery,

Thanks everyone. I think my battery is low, because even though it read as high as 12.1 volts, it was also reading as low as 11.6 volts at times.

Do I need to charge the battery or can I just jump start the tractor?

Hopefully it is not too flooded to start.

A jump works well!

(quoted from post at 17:54:04 04/02/19) A full battery should be close to to
12.6-13 volts. If at only 12 volts and
then you crank, it might be dropping down
to low to give you enough for spark.

What do you get when actually cranking it
with meter ends on the terminals of the
battery?

Click to expand...

Only about 7.8 to 7.9 volts on battery terminals when cranking.

That won't fire it off. Try giving it a
good charge, if it doesn't take the good
charge, then it might have decided to
cross over to the dark side... If it
charges up and maintains a high enough
voltage for a day or two, then good
chance it is ok.

I will charge the battery or jump start it, but I am worried that the dead battery might just be because I have been trying to start it and it will not start. The first time I tried to start it a couple days ago and it did not start, the battery might have been fully charged. I will try to jump it or charge it and see what happens.

John, LISTEN, a so called 12 Volt lead acid battery stabilized at rest that only reads 12 volts IS 50% DISCHARGED

FYI at 67 Degrees 100% charged = 12.61 volts,,,,,,,,,,75% charged = 12.28 Volts,,,,,,,,,50% charged = 11.98 Volts

Charge your battery as its 50% discharged (if your meter is accurate???)

The picture shows an inline series voltage dropping (12 down to 6) ballast resistor that uses a 6 volt coil on a 12 volt
tractor if that's the case with ignition on and a good set of closed points

You should read if alls well near battery voltage on the input (from ign switch) of the ballast and around 6/7 volts on the side that goes to the coil. THOSE VOLTAGES WILL HELP US SEE WHATS THE PROBLEM

Charge the battery, if in doubt have it Load Tested, measure the voltages on both sides of the ballast and the coils input and they should be near what I posted above

John T Retired Electrical Engineer

IF I remember right you had this hauled home in the winter when salt and crud is on the road. Since your battery is low and needs charged. I would unhook all cables and wires connected with the battery and starter, and give them a good cleaning. Wire brush, and baking soda mixed with water to neutralize the acid in any battery clamps, on the battery and reconnect after battery is in good condition.
In your first picture you battery cable looks dirty and corroded. Reason for the cleaning. Be careful not to over tighten the starter bolt and turn the stud there. All the lead clamps need to be tightened is so they don't turn when you twist them after tightening. Not pulled till the ends meet. As everybody else has said for your testing.

(quoted from post at 20:40:19 04/02/19) John, LISTEN, a so called 12 Volt lead acid battery stabilized at rest that only reads 12 volts IS 50% DISCHARGED

FYI at 67 Degrees 100% charged = 12.61 volts,,,,,,,,,,75% charged = 12.28 Volts,,,,,,,,,50% charged = 11.98 Volts

Charge your battery as its 50% discharged (if your meter is accurate???)

The picture shows an inline series voltage dropping (12 down to 6) ballast resistor that uses a 6 volt coil on a 12 volt
tractor if that's the case with ignition on and a good set of closed points

You should read if alls well near battery voltage on the input (from ign switch) of the ballast and around 6/7 volts on the side that goes to the coil. THOSE VOLTAGES WILL HELP US SEE WHATS THE PROBLEM

Charge the battery, if in doubt have it Load Tested, measure the voltages on both sides of the ballast and the coils input and they should be near what I posted above

John T Retired Electrical Engineer

Click to expand...

John T - I will charge the battery and then test out the voltages you mentioned. I will post back when once I test them.

Caterpillar guy - I will also clean the battery when I clean it, you are correct that I hauled it home in the winter on salty roads.

I cannot thank you guys enough, and everyone else, for your help!

File the surface of the points to make sure they don't have a film on them. With the points closed and switch on, open the points with a
screw driver...should have spark. If you have spark it should run.

(quoted from post at 22:17:09 04/02/19) File the surface of the points to make sure they don't have a film on them. With the points closed and switch on, open the points with a
screw driver...should have spark. If you have spark it should run.

Click to expand...

What do you mean open the points with a screwdriver? How would I do this?

You remove the distributor cap, rotor and cover and the points are in sight. If the points are open you can short across with a screwdriver to check for a spark.

casecollectorsc means to use the screwdriver as a lever to swing the moveable point arm away from the fixed side if the points are closed. Dick L is saying use the screwdriver as a "jumper" between the moveable arm and fixed side if the points are open.