how to test alternator.

[Rush55]

when you take cable off battery post tractor dies. I've tested mine years ago but i forgot what I done.

 

[Jim.ME]

when you take cable off battery post tractor dies. I've tested mine years ago but i forgot what I done.

Go to your other post and read my reply.

 

[mdm1]

I did the same thing. My voltmeter was only showing 12v when running. Took it to an auto parts store and they checked it for me on their machine. Failed! If you have it tested you will maybe need to know what the alternator was from. Mines on an Allis G but from a 1978-80 Nissan truck.

 

[Jim.ME]

Lifting a battery cable off was done with generators, they were even run, with their regulator, with no battery in a vehicle by some. An alternator is not like a generator. Lifting a cable off the battery with an alternator can cause a voltage spike and lead to other problems in some vehicles.

 

[old]

when you take cable off battery post tractor dies. I've tested mine years ago but i forgot what I done.

NEVER take a battery cable off a running tractor or other thing while it is running. You can/will smoke test the alternator and if you some how get between the cable in and ground it can hurt you if not kill you. When I was in the Navy one of my E.T. instructors show me that by doing so and the alternator was putting out over 35 volts and 50 plus amps more then enough to kill a man

 

[Janicholson]

when you take cable off battery post tractor dies. I've tested mine years ago but i forgot what I done.

Do not remove the connection to the alternator. Bad policy as it can (and has) been known to raise voltages into the killing range. There is no reason to slash an artery to feel pulse!!!! Jim

 

[Rush55]

Do not remove the connection to the alternator. Bad policy as it can (and has) been known to raise voltages into the killing range. There is no reason to slash an artery to feel pulse!!!!

Do not remove the connection to the alternator. Bad policy as it can (and has) been known to raise voltages into the killing range. There is no reason to slash an artery to feel pulse!!!! Jim

Do not remove the connection to the alternator. Bad policy as it can (and has) been known to raise voltages into the killing range. There is no reason to slash an artery to feel pulse!!!!

Do not remove the connection to the alternator. Bad policy as it can (and has) been known to raise voltages into the killing range. There is no reason to slash an artery to feel pulse!!!! Jim

Do not remove the connection to the alternator. Bad policy as it can (and has) been known to raise voltages into the killing range. There is no reason to slash an artery to feel pulse!!!! Jim

Lifting a battery cable off was done with generators, they were even run, with their regulator, with no battery in a vehicle by some. An alternator is not like a generator. Lifting a cable off the battery with an alternator can cause a voltage spike and lead to other problems in some vehicles.

so if I ran my tractor the alternator wouldn't charge the battery the way i have it wired

 

[Jim.ME]

so if I ran my tractor the alternator wouldn't charge the battery the way i have it wired

IF you wired it using just the 3 wires in the diagram, I posted for you, it will only operate the starter and fuel solenoid. That was what you wanted so you could load it and take it to the vocational school to be re-wired, by them. All other wires were supposed to be unhooked from the switch.

Read the notes I put on that drawing for you. NO Safety switches, No gauges, No charging, No lights.

Here it is again.

 

[Rush55]

IF you wired it using just the 3 wires in the diagram, I posted for you, it will only operate the starter and fuel solenoid. That was what you wanted so you could load it and take it to the vocational school to be re-wired, by them. All other wires were supposed to be unhooked from the switch.

Read the notes I put on that drawing for you. NO Safety switches, No gauges, No charging, No lights.

Here it is again.

View attachment 83458

sorry I was so glad to get it going I missed that.so I'll have to have all new wiring for it to charge the battery

 

[E.B. Haymakin']

so if I ran my tractor the alternator wouldn't charge the battery the way i have it wired

If your wired up correctly, as the tractor's original wiring harness was when it left the factory, the alternator- if not damaged along with possible damage to the battery by arc's and sparks should be just fine. When operated at operational rpm-the motor reved up while mowing will spin the alternator to its highest output. Disconnecting the battery may be shutting the fuel off, a diesel doesn't need electrical to "fire" sparkplugs. I think what happened is power was cut to the fuel solenoid and it closed. Remember, I'm of the opinion that it's likely the battery was damaged by the bad connections at it's posts, I've lost Lord only knows how many batteries by not cleaning those post connections.

 

[Jim.ME]

sorry I was so glad to get it going I missed that.so I'll have to have all new wiring for it to charge the battery

You have a severely compromised wiring harness. To think you can continue using it is just asking for more problems. Wiring harnesses shorting out have caused tractors to be burnt to destruction. some have even led to building fires. Given those facts I am not going to tell you anything but have it rewired.

The only way one could even start to consider reusing the old harness would be to open every inch of the harness and check each wire individually for melted, burnt or shorted spots in each and every wire, one by one.

 

[Jim.ME]

If your wired up correctly, as the tractor's original wiring harness was when it left the factory, the alternator- if not damaged along with possible damage to the battery by arc's and sparks should be just fine. When operated at operational rpm-the motor reved up while mowing will spin the alternator to its highest output. Disconnecting the battery may be shutting the fuel off, a diesel doesn't need electrical to "fire" sparkplugs. I think what happened is power was cut to the fuel solenoid and it closed. Remember, I'm of the opinion that it's likely the battery was damaged by the bad connections at it's posts, I've lost Lord only knows how many batteries by not cleaning those post connections.

His tractor burnt a section of the wiring harness up and melted wires. It wasn't just a bad battery post.

You might want to read through the 226 posts in his thread "Poor Connection".

 

[E.B. Haymakin']

sorry I was so glad to get it going I missed that.so I'll have to have all new wiring for it to charge the battery

For safety a total rewire would be best. Mainly to make sure it's wired back to factory specs, and all wiring is sound/good to prevent a fire and guarantee proper operation-starting. If you identify wires that are damaged and replace them with new wire, and return them to the correct connection location then that would win also. As long the electrical repairs are sound and provide for the proper functioning of the system without "shorting" out.

 

[E.B. Haymakin']

His tractor burnt a section of the wiring harness up and melted wires. It wasn't just a bad battery post.

You might want to read through the 226 posts in his thread "Poor Connection".

I've kept up with it. Y'all have done a lot to help him. Great job.

 

[Rush55]

I've kept up with it. Y'all have done a lot to help him. Great job.

yes they have gone above and beyond helping me and I'm very thankful

 

[E.B. Haymakin']

sorry I was so glad to get it going I missed that.so I'll have to have all new wiring for it to charge the battery

Like these guys have said, your tractor is at risk here. Keep in mind a tractors electrical system needs maintance just like the engine needs maintenance. If corroded connections or cables are not replaced wiring can heat up melting the covering, fuses don't always save the day. Your tractor has been lucky so far. These guys really helped out a lot, and don't want to hear of you still losing your tractor to fire.

 

[Rush55]

Like these guys have said, your tractor is at risk here. Keep in mind a tractors electrical system needs maintance just like the engine needs maintenance. If corroded connections or cables are not replaced wiring can heat up melting the covering, fuses don't always save the day. Your tractor has been lucky so far. These guys really helped out a lot, and don't want to hear of you still losing your tractor to fire.

well hopefully I can get it to the trade as soon I hear from them; I'm also expecting a wiring diagram in the mail and am on a waiting list for a wiring harness

 

[herk]

I have tested mine for years with the engine running I hold my pliers on the back bearing if the back of the alternator on the bearing if it is magnitic the alternator is charging . some alternators have to much stuff to get to or see the back bearing . works on motocraft ,and delco for sure . I showed it to a machanic at the local shop , said he never seen it before, the owner of the shop said he knew of that trick. Bryan

 

[Jim.ME]

well hopefully I can get it to the trade as soon I hear from them; I'm also expecting a wiring diagram in the mail and am on a waiting list for a wiring harness

Good, do not let others get you off the path of a proper repair.

 

[E.B. Haymakin']

when you take cable off battery post tractor dies. I've tested mine years ago but i forgot what I.

when you take cable off battery post tractor dies. I've tested mine years ago but i forgot what I done.

This damage to your electrical wiring is/would be a job to accomplish for advanced tractor mechanics, or a dedicated enthusiast that knows all the details of the functions of every part & component of the tractor. If at all possible get it to the vocational/tech school so their knowledge base can evaluate the level of damage, and work with you on correcting the damage