how to test alternator.

[Rush55]

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

i heard about but forgot. i did that on an old farmall 140. alternator was easy to get 2

 

[Rush55]

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

I am soon

 

[E.B. Haymakin']

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

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

On diesel tractors that utilize the electric fuel cut constant 12v power is sent to the fuel cutoff. As you have discovered I believe from which Hotpoint on your key switch. Until you get the wiring straightened out I wouldn't worry about the alternator right now. I've been through similar problems on my 1997 New Holland and my alternator wasn't damaged.

 

[E.B. Haymakin']

On diesel tractors that utilize the electric fuel cut constant 12v power is sent to the fuel cutoff. As you have discovered I believe from which Hotpoint on your key switch. Until you get the wiring straightened out I wouldn't worry about the alternator right now. I've been through similar problems on my 1997 New Holland and my alternator wasn't damaged.

I had to get the wiring repaired and all was well.

 

[Rush55]

I am soon

well vocational school is going to let me bring tractor to let them work on it as soon as school starts back. I'm so thankful to every body here else I might nor have a tractor. i wander if i coulf use it just a little picking up big limbs in yard

 

[Jim.ME]

well vocational school is going to let me bring tractor to let them work on it as soon as school starts back. I'm so thankful to every body here else I might nor have a tractor. i wander if i coulf use it just a little picking up big limbs in yard

You should be able to as long as only the three wires are connected, and you use a battery charger on the battery to keep it charged up.

REMEMBER, to start it only from the seat as you have no neutral safety starting protection. And keep people away from it when running.

Best to unhook one battery cable when it is setting unused, just to be safe.

 

[Rush55]

You should be able to as long as only the three wires are connected, and you use a battery charger on the battery to keep it charged up.

REMEMBER, to start it only from the seat as you have no neutral safety starting protection. And keep people away from it when running.

Best to unhook one battery cable when it is setting unused, just to be safe.

will do thanks

 

[buickanddeere]

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

I just use the Fluke's clip on ammeter to measure current and then measure the voltage .

 

[Rush55]

will do thanks

I can't begin to tell yall how happy I am to be able to crank my tractor;it may not be the best looking or make but it is a big help after strong winds and hurricanes. I thank God for every one of yall for you advice.

 

[Rush55]

I just use the Fluke's clip on ammeter to measure current and then measure the voltage .

please put that in simple terms for the ignorant and unlearned like me. what is a flukes clip and ammeter

 

[buickanddeere]

please put that in simple terms for the ignorant and unlearned like me. what is a flukes clip and ammeter

Clamp the jaws around the cable leading from the alternator to the battery or ammeter/battery . Reads DC amps .
Switch the meter to DC volts and use the probes between chassis and the alternator output terminal .

 

[Rush55]

Clamp the jaws around the cable leading from the alternator to the battery or ammeter/battery . Reads DC amps .
Switch the meter to DC volts and use the probes between chassis and the alternator output terminal .

Clamp the jaws around the cable leading from the alternator to the battery or ammeter/battery . Reads DC amps .
Switch the meter to DC volts and use the probes between chassis and the alternator output terminal .

what do you mean about jaws my multimeter doest have clips. this is a pic of my alternator.the multimeter that I have looks like this in pic

 

[buickanddeere]

what do you mean about jaws my multimeter doest have clips. this is a pic of my alternator.the multimeter that I have looks like this in pic

Your ammeter is AC amps only . Meter needs to have the DC ammeter option.

 

[Jim.ME]

Your ammeter is AC amps only . Meter needs to have the DC ammeter option.

He has the tractor running, He only has some temporary wiring at this point, no charging system wiring. There is nothing to test. He is taking it to the local vocational school to get it completely rewired.

 

[Rush55]

He has the tractor running, He only has some temporary wiring at this point, no charging system wiring. There is nothing to test. He is taking it to the local vocational school to get it completely rewired.

I wasn't wanting to test just wanting to know how for future reference

 

[used red MN]

I wasn't wanting to test just wanting to know how for future reference

If you double promise me you are not going to attempt to make any changes to the current status of the tractor. With your meter on the 20 volt DC scale as you have it shown in your picture connect it to the battery terminals, red on positive (+) and black on negative (-). With engine off it should read slightly above 12.5 volts. When you start it the meter should then show between 13 and 14 volts. If the unit being tested has lights, a heater blower and A/C all those should be able to be turned on and the 13 - 14 volts maintained. That 13 to 14 volt range is not necessarily set in stone but it is in the “playable” range.

 

[Jim.ME]

I wasn't wanting to test just wanting to know how for future reference

used red MN is right you can use the voltmeter you have to tell if an alternator is charging, by checking the voltage at the battery terminals when the engine is stopped and again when it is running 1200 to 1500 rpms. Many vehicles use voltmeters now instead of ammeters. You do not need an ammeter to see if it is charging, just use your voltmeter, when the time comes.

 

[Rush55]

If you double promise me you are not going to attempt to make any changes to the current status of the tractor. With your meter on the 20 volt DC scale as you have it shown in your picture connect it to the battery terminals, red on positive (+) and black on negative (-). With engine off it should read slightly above 12.5 volts. When you start it the meter should then show between 13 and 14 volts. If the unit being tested has lights, a heater blower and A/C all those should be able to be turned on and the 13 - 14 volts maintained. That 13 to 14 volt

If you double promise me you are not going to attempt to make any changes to the current status of the tractor. With your meter on the 20 volt DC scale as you have it shown in your picture connect it to the battery terminals, red on positive (+) and black on negative (-). With engine off it should read slightly above 12.5 volts. When you start it the meter should then show between 13 and 14 volts. If the unit being tested has lights, a heater blower and A/C all those should be able to be turned on and the 13 - 14 volts maintained. That 13 to 14 volt range is

range

Go to your other post and read my reply.

finally got schematics on wiring. will send you a pic. don't expect yout to do anything. just thought u might want to see it.pic I took wasn't that good

 

[Rush55]

If you double promise me you are not going to attempt to make any changes to the current status of the tractor. With your meter on the 20 volt DC scale as you have it shown in your picture connect it to the battery terminals, red on positive (+) and black on negative (-). With engine off it should read slightly above 12.5 volts. When you start it the meter should then show between 13 and 14 volts. If the unit being tested has lights, a heater blower and A/C all those should be able to be turned on and the 13 - 14 volts maintained. That 13 to 14 volt range is not necessarily set in stone but it is in the “playable” range.

sorry didn't send pics

 

[chris142]

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.

Ya dont do that.