Will this Work ??

Dutchman · Jan 26, 2016

I'm changing my tractor from 6v to 12v .. Question : Do I need to change the coil ?/
it seem to run now but haven't had a lot of seat time yet ....was wondering if the 6v coil would burn up .. or will it be O.K. ??

THANKS for any advice ,,,,,,,,,,, mark

David G · Jan 26, 2016

You will either need to change coil or add resistor in series with coil.

4wdtom · Jan 26, 2016

I think it will work for a while without the resistor, but the condenser will overheat and sort out after a while especially in warmer weather. At least that is the experience I have had. Tom

TomH in PA · Jan 26, 2016

Coil won't burn up, but the points will. A new coil doesn't cost much.

Geo-TH,In · Jan 26, 2016

Like David G said, ballast or A 12 v coil. When you get tired of replacing starter drives, replace starter with 12 volt, I did.

Moonlite37 · Jan 26, 2016

It will burn the points very soon and possibly cause cross fire by arcing the distributor cap.

RJKeith · Jan 26, 2016

YES CHANGE THE COIL. The coil is an auto transformer, by doubling the voltage at the primary, you double the output to the distributor and the plugs, which causes more than rated current, which smokes stuff fast.

Case Nutty 1660 · Jan 26, 2016

Mark, here is what I did over 30 years ago to my VA, this is a Dodge resistor block used on them for years, drops volts to 6 or 8 volts, the starter on mine has never given me a problem in all those years, I assume you are working on your VAC. I also made a new ground cable and bolted it right to the starter base as that old tin work does not always ground the best. Oh and thanks for the question as I see a bolt came out of my tin work when I raised the hood.
cnt

jeffcat · Jan 26, 2016

On some systems the "12" volt coil is not twelve. It is actually an "8" volt coil. The ballast resistor is needed to keep things from blowing up. When you turn the key to start and the solenoid closes that extra post on top shoots straight power to your coil. Now as the starter starts to turn it is sucking the 12 volts from the battery down to 8 volts. This hodge podge lets your coil have a really good spark. When the engine starts and the solenoid is now open, the resistor is in line and with 12 volts going in and 8 volts coming out to the coil. Sounds nutty but it works. Anyone else have something to add? Far as I know this is how they work.

mj · Jan 26, 2016

(quoted from post at 16:44:57 01/26/16) Mark, here is what I did over 30 years ago to my VA, this is a Dodge resistor block used on them for years, drops volts to 6 or 8 volts, the starter on mine has never given me a problem in all those years, I assume you are working on your VAC. I also made a new ground cable and bolted it right to the starter base as that old tin work does not always ground the best. Oh and thanks for the question as I see a bolt came out of my tin work when I raised the hood.
cnt

I have 3 or 4 (CRS) VAs set up this way and all have worked good for years. I had a 12v coil on a couple but went back to 6v coil with resistor after they went south. 8)

jeffcat · Jan 26, 2016

Case Nutty, May I add a little hint. I only see the one supply wire to the resistor. Does you solenoid have one or two terminals on it's side. Try a double post one and run the out put post wire to the coil side of the resistor. See if you tractor will even start faster in cold weather. If it starts fine then ignore this. I know when I converted the 300U from 6 to 12 I had to do that. Cold weather it just wouldn't start. This way it pops right off. Science class.

mj · Jan 26, 2016

(quoted from post at 16:45:13 01/26/16) On some systems the "12" volt coil is not twelve. It is actually an "8" volt coil. The ballast resistor is needed to keep things from blowing up. When you turn the key to start and the solenoid closes that extra post on top shoots straight power to your coil. Now as the starter starts to turn it is sucking the 12 volts from the battery down to 8 volts. This hodge podge lets your coil have a really good spark. When the engine starts and the solenoid is now open, the resistor is in line and with 12 volts going in and 8 volts coming out to the coil. Sounds nutty but it works. Anyone else have something to add? Far as I know this is how they work.

Most ignition switches have a 'start' terminal that supplies 12v to the solenoid and to the coil, bypassing the resistor during start up; since my VAs and Oliver 60 have a start button (no solenoid) I don't use that terminal - just turn the key switch to 'on' and push the start switch.

Dutchman · Jan 26, 2016

THANKS GUYS .... I will go to my parts store tomorrow after work and get a resistor or coil ..

THANKS again ..... mark

Case Nutty 1660 · Jan 26, 2016

Jeff,,, the VA series have a starter button inline in the Batt wire, no solenoid, this way works very well in all temps,
cnt

big jt · Jan 26, 2016

OK I am clearly the deviant here.

I have run a Allis WD45 for 20 years on the 6 volt coil with no resistor. Actually two 45's and a Silver King this way. One of the 45's was our main mower so it ran every week without fail. I think I have touched up the points once in that time. If you are changing the polarity of the ground change the primary wires on the coil, but leave the resistor out of the mix.

Actually we had resistors on two of these tractors and they gave more problems then they were worth. Took them off and never looked back.

jm2cw

jt

Will this Work ??

Dutchman

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David G

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4wdtom

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TomH in PA

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Geo-TH,In

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Moonlite37

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RJKeith

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Case Nutty 1660

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jeffcat

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mj

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mj

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Dutchman

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Case Nutty 1660

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