Ignition coil

Farmall B & BN Tractors, 1939-1947
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Tractor Rod
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Ignition coil

Postby Tractor Rod » Tue Jul 05, 2022 6:17 am

My B was running great and died suddenly. No spark to plugs but power to the coil. The coil was new six months ago with maybe 2 hours in it. Could it have gone bad and how do I test it?

Thanks in advance for helping!

Eugene
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Re: Ignition coil

Postby Eugene » Tue Jul 05, 2022 7:03 am

The test is to replaqce with a known good coil.
I have an excuse. CRS.

BullDAWG
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Tractors Owned: 1950 Super A
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Re: Ignition coil

Postby BullDAWG » Thu Jul 07, 2022 8:06 pm

One thing that will kill a coil fast is if tractor has been converted to 12v and no resistor added to hot wire to coil. If it's 12v buy a coil w/ built in resistor. Then you don't need to have external one and they are about same price saving you some $ & time.
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Eugene
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Re: Ignition coil

Postby Eugene » Fri Jul 08, 2022 11:43 am

BullDAWG wrote:One thing that will kill a coil fast is if tractor has been converted to 12v and no resistor added to hot wire to coil. If it's 12v buy a coil w/ built in resistor. Then you don't need to have external one and they are about same price saving you some $ & time.
Ignition points require around 6 to 9 volts to function without arcing/burning. 12 to 14.5 volts to the ignition points and they will arc/burn.
I have an excuse. CRS.

BullDAWG
10+ Years
10+ Years
Posts: 855
Joined: Fri Dec 30, 2011 6:09 pm
Zip Code: 39401
Tractors Owned: 1950 Super A
1955 John Deere 60 (sold)
1950 Cub (sold) 1950 Cub l59 woods belly mower (sold)
1951 Cub (sold) 1950 Cub w/ 5' sicklebar (sold)
Tufline 6' disc (old heavy pull type)
1953+ A-295A 2 furrow SlatWing Plow Chief plow (SA)
1950 cub-193 1 furrow SWPC plow (cub) (sold)
6' home made bush hog. Mounts on drawbar
Circle of Safety: Y

Re: Ignition coil

Postby BullDAWG » Fri Jul 08, 2022 1:30 pm

Eugene wrote:
BullDAWG wrote:One thing that will kill a coil fast is if tractor has been converted to 12v and no resistor added to hot wire to coil. If it's 12v buy a coil w/ built in resistor. Then you don't need to have external one and they are about same price saving you some $ & time.
Ignition points require around 6 to 9 volts to function without arcing/burning. 12 to 14.5 volts to the ignition points and they will arc/burn.


OP was talking about coil going bad, I was just saying if it was converted to 12v that might explain why coil went bad so fast. But Rod does need to check points and condenser also as they will also cause a no fire condition.
ImageCircle of Safety
"The nine most terrifying words in the English language are: I'm from the GOVERNMENT and I'm here to HELP."
"I DON'T believe in a government that protects US from OURSELVES." R. Reagan

Tractor Rod
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Posts: 72
Joined: Sun Dec 27, 2020 10:48 am
Zip Code: 67357

Re: Ignition coil

Postby Tractor Rod » Fri Jul 08, 2022 1:47 pm

Thanks all. I bought a new coil and it fired right up. I do have an external resistor in line so should be good to go. Thanks again…I love my B!


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