Farmall H alternator

[Devin Arends]

I have an H that was converted to a 12 volt before I bought it. The problem I am having is the battery is not charging. Once I charge the batter it will start the tractor a couple dozen times and then die. Once the tractor is running it runs great.

I am pretty sure the problem has to be the alternator. My question is this, can the tractor still run if the alternator is not working?

 

[horsepoor]

I am pretty sure the problem has to be the alternator. My question is this, can the tractor still run if the alternator is not working?[/quote]

Yes. Just like a car with a bad alternator, you will run off the battery til it dies. Take the alternator in to an auto zone, oreilleys, etc, for a free spin. They will tell you if it is bad or not. If it is a 10 SI GM alternator, a reman for a 1976 Chevy pickup is $29.99 with a core exchange.

-Horsepoor

 

[rustred]

if you have a distributer it will run till battery goes dead, then engine will stop.
with magneto it makes no difference as battery is only for starting as mag is producing the spark.

 

[Dave from Texas]

Is the alternator excited? Meaning do you have 12V on terminal 2 for a short time. On mine a lot of times I have to jump the 12V and then it starts charging. The little lights and resisters don't always work. The engine RPM is not high enough.

 

[Devin Arends]

I excited the alternator and it started charging. My set up does not have a resistor or warning light.......dont know what they are good for. So, now we have a new problem. Now that the alternator is working the engine will not stop when I turn the ignition off. I believe my father-in-law put the ignition on backwards.

 

[horsepoor]

So, now we have a new problem. Now that the alternator is working the engine will not stop when I turn the ignition off. I believe my father-in-law put the ignition on backwards.[/quote]ttps://ytforums.ytmag.com/photos/1000.jpg[/img]

 

[teddy52food]

Well that is what the light is for. It lets enough through to excite the alt, but won't let enough through to feed the ign.

 

[horsepoor]

(quoted from post at 03:35:16 05/12/11) Well that is what the light is for. It lets enough through to excite the alt, but won't let enough through to feed the ign.

I added a diode as well thinking the 100 mA lamp would be too small to get the job done on its own. Any thoughts on that? Wondering about that before I change any more. It may be overkill, but a 10 pack of Diodes cost $1.49 The lamp cost $2.49 for a two pack. That would be 15 cents for the diode and $1.25 for the lamp per tractor.

-Horsepoor

 

[Larry in WNY]

Turn the diode in the opposite direction and see if that allows you to shut it down. They are suppose to prevent current from flowing backwards so make sure it's connected correctly.

Larry

 

[Devin Arends]

I see you have three wires coming from your alternator on your diagram. Why do I only have two coming from the alternator? I dont have the wire that runs from one part of the alternator to the other part. Also, is the positive or negative of the coil attached to the distributor??

 

[horsepoor]

(quoted from post at 00:55:41 05/13/11) I see you have three wires coming from your alternator on your diagram. Why do I only have two coming from the alternator? I dont have the wire that runs from one part of the alternator to the other part. Also, is the positive or negative of the coil attached to the distributor??

The pigtail to the charging stud on the back of the alternator from terminal 2 is used because originally it was the sensing the voltage drop. Your tractor doesn't have a mile long wiring harness like a 70s or 80s era auto. Voltage drop would be minimal. The terminal 1 goes to the idiot light set up. I used an automotive coil. The "battery" terminal is where your line from the terminal block with the key switch and other side of the indicator lamp tie in.

 

[Devin Arends]

Thanks!!

 

[David G]

You never put diodes in parallel, one of them will carry all the current
and the rest will watch.

 

[horsepoor]

(quoted from post at 00:57:05 05/14/11) You never put diodes in parallel, one of them will carry all the current
and the rest will watch.

If you are referring to the pic, that is from the radio shack web site, NOT the way it is installed. You only use one diode, but they come in a 10 pack like that photo.

-Horsepoor