Automobile genny on 841 - which VR and coil?

William Fissell · Mar 7, 2014

Hi,

I seem to have an automobile genny on my 841 based on the four cooling slots I see, which have been filled in with putty for some reason. This may explain why I see 10V on what is 'advertised' as a 6V system- ie it has a 6V batt, 6V regulator

The genny motors medium speed at 6v.

1- Any further testing I should do? I suppose someone might once have rewound the genny to be 6V but that seems a stretch.

2- there's a ton of Echlin 12V regulators at NAPA. The only 12V conversion I have done before is with a 10si - any suggestions?

3- 12V coil - will the NAPA IC10 do fine?

thanks!

BIll

souNdguy · Mar 7, 2014

since I can remember, this forum has reccomended the napa IC14sb round coil for 12v applications.

I see no reason to deviate.

as to your gen / reg situation..

I find it extremely hard to believe you are seeing a closed circuit voltage of 10v in a system with a 6v battery.

IF the gen was making 10v at load. something would have let smoke out long ago!.. thus i suspect your testing or observation procedures are in error.

is it still set up as B circuit?

what does a full field test show you on the ammeter thru a range of rpms from idle on up?

William Fissell · Mar 7, 2014

Soundguy,

I kinda agree on the smoke issue. For example, the battery is fried and won't take a charge on the charger. The VR does nothing- ie the contacts aren't chattering, plus bits of the wiring harness had burned/melted through.

I redid the harness and turned it on just.... long... enough.... to....see... 10V...and shut it down right away. Less than 60s.
The 10V was on an old fluke DMM that I have used to troubleshoot my 9N, my Jubilee, and my 600. I'm not really buying this analog-meters-only argument, but I picked up a simpson 260 on fleabay and will try it again with that.

No ammeter on an 841- they substituted a gas gauge. I don't have a clamp-on so I'll have to kludge one up.

I assumed it was a B circuit based on the year but will reconfirm if you tell me how. It def has a 6V regulator.

thanks for the help!

souNdguy · Mar 7, 2014

I was kinda hopin you had an ammeter int he tool box to toss inline. they are great diagnostic tools. way better than a olt meter or idjit lamp if you can only have 1.

William Fissell · Mar 7, 2014

The genny motored with arm and fld to battery- I think that confirms its a B circuit.

souNdguy · Mar 7, 2014

generally yes.. however technically it should motor with just arm and case and residuals. but.. with 50ys of dirt and rust. many times it's not smooth enough to do so.

Lanexa Speedway · Mar 7, 2014

Some info for doing a "stealth" 12V conversion that uses a Ford car or truck generator (or a tractor one), instead of a 10SI.

http://forums.yesterdaystractors.com/viewtopic.php?t=1101464&postdays=0&postorder=asc&start=0

Also put "stealth" in the search box and you'll find other good stuff.

Hope that helps,
Kevin

Texas! · Mar 7, 2014

I would use a 12V regulator for an 841D. They were rated at relatively low amperage so regardless of which generator you have you won't melt it by trying to get too many amps out of it with a regulator rated for higher amperage.

Tony Jacobs · Mar 7, 2014

Hello William , Yes it is a B circut generator , 12 volt car , truck and tractor are the same except tractors have only one cooling slot on the bottom cars and trucks have the four because they are under the hood protected from the water and pulleys are different diameters . You need NAPA voltage regulator number VR 953 . NAPA coil number IC 10 is correct with a NAPA resistor number ICR 11 . All 01 series tractors have fuel gauges with generator lamps from the factory no one substituted it in yours . Thanks Tony

William Fissell · Mar 8, 2014

thank you tony-- I meant Ford substituted it

I'll likely need an ammeter to sort this all out

William Fissell · Mar 8, 2014

OK, I have a lot of big black bird (crow) to eat. Turns out y'all were right and using an analog meter DID give me a different answer.

1- measured voltage with engine running about 800 rpm: 6.2V across (fresh) battery terminals. 6.2 V at the arm and at the field terminals of the genny.

2- looped in an old inductive ammeter between bat and battery, full fielded it by jumping arm to field, got the ammeter pinned. (pinned negative, but I probably have the inductive ammeter on backwards). I didn't measure volts because I only had 2 hands and I didn't want to drop my nifty new Simpson 260.

Attached is a photo of the genny.

Automobile genny on 841 - which VR and coil?

William Fissell

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souNdguy

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William Fissell

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souNdguy

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William Fissell

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souNdguy

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Lanexa Speedway

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Texas!

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Tony Jacobs

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William Fissell

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William Fissell

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