Generator Light

[RoamingGnome]

What was hiding under the cover of the regulator on my Case 195
I also had the generator light blues... Putting in a new regulator fixed the light and put a on my face

[myerslawnandgarden]

I didn’t test voltage at the F terminal.


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I don't usually bother to check voltage at the "F" terminal. The regulator varies the resistance between the "F" terminal (field winding) and ground. Open and there is no charge, zero resistance= full charge, some resistance gives a charge rate somewhere in between.

The easiest way to determine whether you have a generator or a regulator problem is to follow these steps:

1) Check battery voltage with engine off and note the value.

2) Start the engine and again check voltage at mid to 3/4 throttle. You should see and increase if the charging system is functioning, if not there is a problem.

3) Next, with the engine again running at 1/2-3/4 throttle, momentarily ground the "F" terminal either with a jumper wire or simply by shorting the terminal to the case of the generator with a screwdriver. This puts the generator into full charge mode. If it is capable of producing output, the generator light will go out, if you have an ammeter you will see full charge, usually 15 amps with a Delco Remy starter/generator.

A) No change in the gen light or ammeter, you have a generator problem

B) If you see full charge by voltmeter at the battery, gen light goes out or ammeter pegs itself you have a good generator and a bad regulator.

Hope this helps,

Bob

[RoamingGnome]

Thanks @myerslawnandgarden - That is a really useful step by step troubleshooting list...
I think I'll be that into one of my manuals so I don't forget!
Gerry

[Harry]

Yes thanks Bob. I too will note this explanation and save it. I use to be able to remember information like this but not any more. I need to keep notes for future reference. Thanks again Bob. Harry

[findwaldo]

Thank you, Bob for your troubleshooting steps. I finally had some time today to tackle this.

The battery voltage to start was 12.79 started the tractor and saw no increase in voltage. I then went on to step 3 and tried grounding the F terminal … no change. So, this points to a generator problem.

I started to reference a post I saw on this page:

https://simpletractors.com/forums/topic ... rator-bad/

3rd post down by Maxwood. Very informative.

I started following Maxwood’s troubleshooting when Bob’s showed the generator was bad.

I went to step 2 got a resistance reading of 7.8-7.9. Low but okay.

Step 3 looked okay

Step 4 I didn’t have a 0 ohms, so no shorted armature. So I proceeded to blow out the commutator and windings.

I topped off my battery with a charger, and put it all back together to test.

I started the tractor and all looked good. No generator light. The battery was charging, around 14 volts. I put a positive meter lead on the Generator A terminal and the negative lead on the battery negative terminal. It looked like the generator was putting out 14-15 volts. It continued like this for about 5 minutes. I kept measuring throughout the 5 minutes and the voltage readings were consistent. Then the generator light turned on. I measure the generator A to negative battery and was getting 1-2 volts. Battery voltage was 12 something … not charging.

It seems really odd to me that it’s working great one minute, and then it’s like a switch flips and the generator goes from putting out 15 volts to 1-2 volts. At this point I tried grounding the F terminal again, but no change in voltage. The way it’s acting makes me think regulator, but because grounding the F terminal does nothing, it must be something glitchy on the generator…


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[myerslawnandgarden]

If grounding the "F" terminal after the no-charge indication and there was no change, there is a problem with the generator. Sounds like it works sometimes and then not.

I think that I would return it to the rebuilder for testing.

Bob