coil in 8n 12v burns out

Michael VG · New User Joined: 03 Oct 2012 Posts: 5 Report to Moderator

Have a 1947 8N Ford converted to 12v. It burns out the coil after about 8 to 10 hours of run time. How do I fix it?

JMOR · Posted: Wed Oct 03, 2012 2:20 pm Post subject: Re: coil in 8n 12v burns out

Michael VG · New User Joined: 03 Oct 2012 Posts: 5 Report to Moderator

12v coil. I do not know which resister it has.

Michael VG · New User Joined: 03 Oct 2012 Posts: 5 Report to Moderator

Oh, only on balist resister.

JMOR · Last edited by JMOR on Wed Oct 03, 2012 2:55 pm; edited 1 time in total

If you have the 12v coil and the factory ballast resistor (3 terminal board with resistor in back of dash), it should not be burning up coils in 8 hours run time.
Walking away with stalled engine & key on will usually ruin one, but otherwise, hundreds do this successfully. You should verify that the resistor is actually wired into the circuit.....a mis-connected wire could leave the resistor out of the circuit, even though it is physically present.

Darrellbud · New User Joined: 17 Aug 2011 Posts: 3 Report to Moderator

I have just replaced the coil on my 8n with a new coil right out of the box that was bad. I bought another and it was also bad brand new right out of the box. Just because your coil is new, or has spark on a bench test dose not mean it is good My tractor is living proof of that. My tractor ran but it ran terrible I kept resetting the points and going over everything else only to fine out the new coil's were bad right out of the box. Put your coil on another tractor and make sure it will supply consistant power to run your tractor. Has anyone else had this problem or am I just unlucky.

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