140 Charging

How do I correctly test my 140 with a voltmeter to see if it"s charging properly? It"s a 12 volt system with generator.

With it running at 1/2 throttle or higher it should be reading between 14.2 and 14.6 volts when the volt meter is placed across the battery posts. (not the clamps, the actual battery posts)
If it is within this range, it is great. If the meter you are using is going all over the place with numbers it is because the digital meters of modest cost try to read DC as though it were pure. DC in a generator charging system is far from pure, it is a noisy irrational average of voltages that amount to a charging event. An analog (needle type) meter is much more accurate in this environment. (or a Fluke quality professional DMM)
If the amp meter is not showing charge, and the volts are OK it needs to be determined if someone wired the amp meter wrong. or it is stuck and not moving (common).
If it is showing low charging volts, 12.4 to 12.6, then use a jumper wire (with it running as above) to temporarily ground the F (small) terminal on the Generator. If it now charges a bunch, I would replace the Voltage regulator.
John T has a charging system analysis list in the archives that is too long to repeatedly copy to the response. So use the archives to find-- John T charging system trouble shooting --. JimN

Jim, I sure agree with the use of an analog needle voltmeter NOT any fancy schmancy jumpin all over digital readout lol. I still have an old Simpson 260 and an RCA WV 38A. Put that on the battery and it will usually stabilize in the 13 to 14 and a lil over voltage range ifffffffffffff shes charging properly. Although the battery acts like a big capacitor to smooth out that low cycle pulsing DC wave, digital meters dont like that in my experience.........

John T

John T - I too use an ancient Simpson 260 - also a vintage Triplett 630 - for tractor electric diagnosis.

I find that for "noisy" tractor electrics the old analog meters perform better (and the readings are easier to interpret) than even my industrial-rated Fluke 87 DMM.

Incidentally I rescued both the analog meters from scrap tubs at work when the plant spark chasers all switched over digital multimeters about 20 years ago. ...Bob M

I to have a Simson black box looking meter, and a GE VTVM , and a 150.00 DMM from silicon valley, And a Certified fancy Schmancy Fluke.
Analog on my old stuff without fail. Jim

Hi and thanks for the advice,
I tested as per your suggestions and am only getting a steady 11.6 volts with a digital voltmeter. I polarized the generator and still 11.6 volts. When the tractor is running, the ammeter moves ever so slightly to the discharge direction. I didn"t try grounding the generator yet. I"m a novice at this and afraid if I make a mistake I might damage something in the electrical system. So I need everything explained to me very simply. I tried to find the article by John T in the archives but was unsuccesful. Does someone have the exact title?

(quoted from post at 10:51:17 11/18/08) Hi and thanks for the advice,
I tested as per your suggestions and am only getting a steady 11.6 volts with a digital voltmeter. I polarized the generator and still 11.6 volts. When the tractor is running, the ammeter moves ever so slightly to the discharge direction. I didn"t try grounding the generator yet. I"m a novice at this and afraid if I make a mistake I might damage something in the electrical system. So I need everything explained to me very simply. I tried to find the article by John T in the archives but was unsuccesful. Does someone have the exact title?

Click to expand...

ook here:

http://www.ytmag.com/cgi-bin/viewit.cgi?bd=farmall&th=665110

http://www.ytmag.com/cgi-bin/viewit.cgi?bd=farmall&th=665110