[73deereh3]

Hey guys,

I have a 73 140 H3 and was wondering how you know what amp stator is in it(10 or 15)? Problem I'm having is the tractor doesn't charge when the pto is engaged. I tested the stator and got 25 amps (ac) which I thought might be enough if the stator is a 10 amp. I am leaning towards the stator being bad but was just hoping maybe it's just the rectifier/regulator as that is much easier to change out!

 

[wyogreen]

Andrew,

At serial number 38001 and above they went to the 15 amp stator.
I'm guessing you meant to type 25 volts AC out of the stator you have, which should mean it's ok. The regulator takes that 25 Volts AC, and converts it to 13 volts or so of DC to charge the battery. So with the engine running at a fair clip, you should read about 13.6 volts at the battery.
You may want to check to be sure the battery and regulator are grounded good.

Steve

 

[73deereh3]

Ok so I must have the 15 amp stator as mine is a 50000 something serial number. Regulator/rectifier ground the it's own case to the body correct?
Yea when I tested the stator at full throttle it read 25 volts ac, is that enough?

 

[wyogreen]

Andrew, the service manual says at full throttle you should see 28 to 32 volts AC. That's with the 3 prong connector unplugged from the regulator. It goes on to say "if no charge is being received by the battery (0 ammeter reading) and voltage is more than 25 to 28 volts, the stator is producing properly. Therefore, by process of elimination, the rectifier-regulator must be at fault"

The regulator DC side gets to ground thru its case to the body, same as the battery.

 

[cwodan]

I had/have an issue with my 1970 h3 10 amp charging system. I changed stators twice and with the two and original I was reading 18vac (full throttle) coming out of the two stator wires at the regulator. Book says 28-32vac is required. I changed the flywheel tonight and now I am getting 23.5 VAC at full throttle but still no charge showing. I have a new wire harness and all is hooked up correct. Just wondering if I could get some of you with a 10 amp system to let me know what you are reading coming out of your stator??? I might have a regulator problem as well but at the same time I am not getting the required 28vac to the regulator according to the shop manuals troubleshooting steps. I am hoping someone has the same voltage and their system is charging. Pulling this engine is getting old. Thanks for any assistance.

 

[wyogreen]

If I remember right, I get around 28 or 29 volts out of my stator at full throttle. The slower the engine runs, the less the output. The DC output of the regulator is roughly 1/2 of the input AC, which means you are putting out about 12 volts DC. That wouldn't be enough to charge the battery. You want around 13 volts or so.
You might want to make sure your engine is actually at full rated RPM's before you go much further.

Steve

 

[cwodan]

Thanks for the reply Steve.