10 Amp current when battery connected

[Rheindel]

Hello,

I bought an 1949 N8 which is not converted to 12V.
Its running but the battery drains. So I wanted to check if its charging while the tractor is running. I get weird readings from my volt meter as if I am trying to measure AC voltage. I would have expected something like 6.5-7V. Without the tractor running I get 6.1V on the battery. I also notice a strong arc when connecting the batter terminals and measured the current. I would have expected to be zero amp without anything running. It almost looks something is grounded.

Is the voltage regulator bad or do I need to polarize?

thanks and regards,
Rheindel

 

[Jim L WA]

First of all, using a digital meter while the engine is running will cause crazy reading due to the meter picking up induction from the ignition.
Then, you are going to have to disconnect wires, one at a time to find the short to ground. Do an internet search for JMOR wiring diagrams, and print out the one that fits your tractor. Use that to start lifting wires one at a time to find the culprit. It very will could be a voltage regulator, but could also be frayed or burned wires.

 

[JMOR]

(quoted from post at 12:29:09 10/13/22) First of all, using a digital meter while the engine is running will cause crazy reading due to the meter picking up induction from the ignition.
Then, you are going to have to disconnect wires, one at a time to find the short to ground. Do an internet search for JMOR wiring diagrams, and print out the one that fits your tractor. Use that to start lifting wires one at a time to find the culprit. It very will could be a voltage regulator, but could also be frayed or burned wires.

irst on I would disconnect is the generator armature.

 

[Rheindel]

Thanks Jim,

I found the wiring diagram and checked all cables... nothing suspicious. But one thing seems to be wrong. Is it normal that I can crank the starter by pressing the starter switch with the key in the off position?

Edit: It seems normal that the starter cranks without the key in on position.

I think I found the problem. It's the distributor. When I disconnect the red wire from the distributor no more current drains the battery. Could you confirm that is the problem?

Many thanks,

- Rheindel

This post was edited by Rheindel on 10/13/2022 at 01:43 pm.

 

[TheOldHokie]

(quoted from post at 15:57:28 10/13/22)
Thanks Jim,

I found the wiring diagram and checked all cables... nothing suspicious. But one thing seems to be wrong. Is it normal that I can crank the starter by pressing the starter switch with the key in the off position?

- Rheindel

Perfectly normal. Do as JMOR suggested and your discharge will probably stop.

TOH

 

[Rheindel]

Thanks, I found the discharge. Happens through the red cable connecting to the distributor. If I disconnect the red from the distributor the discharge stops.

- Rheindel

 

[JMOR]

(quoted from post at 16:49:20 10/13/22)
Thanks, I found the discharge. Happens through the red cable connecting to the distributor. If I disconnect the red from the distributor the discharge stops.

- Rheindel

ell, my friend, if you had ign ON and engine stopped with points closed (normal), then coil current would be present. Absolutely normal. Doesn't sound to me as there is any problem.

 

[Jim L WA]

(quoted from post at 14:21:37 10/13/22)

(quoted from post at 16:49:20 10/13/22)
Thanks, I found the discharge. Happens through the red cable connecting to the distributor. If I disconnect the red from the distributor the discharge stops.

- Rheindel

ell, my friend, if you had ign ON and engine stopped with points closed (normal), then coil current would be present. Absolutely normal. Doesn't sound to me as there is any problem.

Probably right on JMOR. I was going by the title of his post where he said he had a 10 amp draw.

 

[Rheindel]

ok, thanks. That is clear now. The discharge is normal if the points are closed.
Found an old analog voltmeter and checked the voltage on the battery when the tractor was running. Exactly the same voltage as if not running. 6.1V Not sure if this is normal for a 6V system but seems low, right?

thanks again.

 

[JMOR]

(quoted from post at 18:17:23 10/13/22) ok, thanks. That is clear now. The discharge is normal if the points are closed.
Found an old analog voltmeter and checked the voltage on the battery when the tractor was running. Exactly the same voltage as if not running. 6.1V Not sure if this is normal for a 6V system but seems low, right?

thanks again.

ot normal, not charging....IF you have half throttle or more.

 

[HCooke]

Is it normal that I can crank the starter by pressing the starter switch with the key in the off position?

On an 8N that is normal.

 

[Rheindel]

I had it running on all different speeds.. no change in voltage.
Any procedure to check the alternator?

Thanks

 

[JMOR]

(quoted from post at 18:59:56 10/13/22) I had it running on all different speeds.. no change in voltage.
Any procedure to check the alternator?

Thanks

o you really have a 6v 'alternator'?

 

[Abbby]

we should stay on your original issue. Current draw with engine shut off. With key off when you remove a battery cable there should be no arcing or current draw. Like suggested earlier you should disconnect one circuit at a time to find which one is shorted out and resolve that issue.

 

[Eman85]

(quoted from post at 15:17:23 10/13/22) ok, thanks. That is clear now. The discharge is normal if the points are closed.
Found an old analog voltmeter and checked the voltage on the battery when the tractor was running. Exactly the same voltage as if not running. 6.1V Not sure if this is normal for a 6V system but seems low, right?

thanks again.

Discharge is not normal with the switch in the off position.
Let's go back to the original problem. You should not get an arc when connecting the battery if everything is shut off. You should not have any current draw with everything shut off.

 

[Blue Jay]

(quoted from post at 18:52:56 10/13/22) Is it normal that I can crank the starter by pressing the starter switch with the key in the off position?

On an 8N that is normal.

Yes it is.

 

[JMOR]

(quoted from post at 10:49:01 10/14/22)

(quoted from post at 18:52:56 10/13/22) Is it normal that I can crank the starter by pressing the starter switch with the key in the off position?

On an 8N that is normal.

Yes it is.

ey, BJ, I m-sure Mr.Cooke appreciates you informing him of his correctness.

 

[Rheindel]

(quoted from post at 07:41:25 10/14/22)

(quoted from post at 15:17:23 10/13/22) ok, thanks. That is clear now. The discharge is normal if the points are closed.
Found an old analog voltmeter and checked the voltage on the battery when the tractor was running. Exactly the same voltage as if not running. 6.1V Not sure if this is normal for a 6V system but seems low, right?

thanks again.

Discharge is not normal with the switch in the off position.
Let's go back to the original problem. You should not get an arc when connecting the battery if everything is shut off. You should not have any current draw with everything shut off.

Thank you.
I was not aware that a discharge through the distributor contacts is normal when the key is in ON position. No discharge when key is in OFF. So that 'problem' is solved.

 

[JMOR]

So, moving on, do you have a generator or alternator?

 

[Rheindel]

yes, still not charging the battery. I found some diagnostic tests in the forum:

Two jumper wires & voltmeter will yield some quick information. Measure battery voltage before starting anything. Start tractor and note if battery voltages increases with engine speed. While running at speed, connect jumper from generator Field terminal to ground and again observe battery voltage for change. Next, leaving field jumper in place, connect another jumper wire from generator armature to non-grounded battery terminal, and note change in battery voltage. Remove Armature to battery jumper before stopping engine. Report voltages observed at each step.

Result:
No change in voltage after adding first jumper and also no change after adding second jumper.

 

[JMOR]

(quoted from post at 15:13:47 10/15/22)
yes, still not charging the battery. I found some diagnostic tests in the forum:

Two jumper wires & voltmeter will yield some quick information. Measure battery voltage before starting anything. Start tractor and note if battery voltages increases with engine speed. While running at speed, connect jumper from generator Field terminal to ground and again observe battery voltage for change. Next, leaving field jumper in place, connect another jumper wire from generator armature to non-grounded battery terminal, and note change in battery voltage. Remove Armature to battery jumper before stopping engine. Report voltages observed at each step.

Result:
No change in voltage after adding first jumper and also no change after adding second jumper.

believe that I wrote that. Results indicate generator is bad. You can disassemble it and inspect the brushes, brush springs, and commutator.

 

[Rheindel]

Thanks. I didn't want to mess around and converted to 12V. Starts like a champ and is charging.