The Ford Barn

Bill Goddard · 07-15-2020, 07:02 PM

I have a problem with coil resistance. I think I am doing everything right by using a 1.5-ohm coil with a 1.5-ohm ballast resistor and a 12volt coil.

When I run the car up to 45mph I get cutouts and some backfire. The coil gets too hot to handle. This cutting out could be a fuel problem but the coil should not get so hot should it?

I just read today the extensive discussion on cutting out at high speeds from some years ago but it didn't help me much. However; I have concluded that that the habit of mounting all coils on the model A terminals down is wrong. Oil-filled coils should be mounted terminals up and epoxy filled coils can be mounted terminals down.

This resistance and 6v/12v coil business are driving me nuts. Can anyone explain why I need a 1.5-ohm resistor with a 1.5 -ohm 12v coil or no resistor with a 12volt 3-ohm coil? I have a 12volt neg grnd car.

Thanks, Bill G

07-15-2020, 07:02 PM	#1
Bill Goddard Senior Member Join Date: May 2010 Location: Shrewsbury,Pa Posts: 516	Coil Resistance I have a problem with coil resistance. I think I am doing everything right by using a 1.5-ohm coil with a 1.5-ohm ballast resistor and a 12volt coil. When I run the car up to 45mph I get cutouts and some backfire. The coil gets too hot to handle. This cutting out could be a fuel problem but the coil should not get so hot should it? I just read today the extensive discussion on cutting out at high speeds from some years ago but it didn't help me much. However; I have concluded that that the habit of mounting all coils on the model A terminals down is wrong. Oil-filled coils should be mounted terminals up and epoxy filled coils can be mounted terminals down. This resistance and 6v/12v coil business are driving me nuts. Can anyone explain why I need a 1.5-ohm resistor with a 1.5 -ohm 12v coil or no resistor with a 12volt 3-ohm coil? I have a 12volt neg grnd car. Thanks, Bill G