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Re: 8N not firing
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Posted by John T on March 09, 1999 at 11:10:22:
In Reply to: 8N not firing posted by Steve F. on March 09, 1999 at 10:52:55:
Steve, it sounds like youre technically well versed so I will skip the preliminarys. I will just give you more info and then maybe you can diagnose the problem. Of course, the high side (+ where it connects to lead from switch and ballsat resistor) of coil reads battery voltage when the points are open but should drop to about half that when points are closed. Because, then, current is being drawn and about half the voltage is dropped across ballast resistor and other half across coil. Also of course, when points are closed, the low side of coil goes to zero volts because its effectively connected to ground via the points. To fire the coil, the points gotta be closed conducting current, but then the points gotta open before the high secondary voltage develops. I wonder if your contact points are failing to close as they should??????? Place a test light on the coil low - side and crank the engine, the light should go on and off (when points closed) but if it never goes off, youre points are never closing and conducting. You can test the coil on a bench using a plug and jumper wires and a battery to see if its good, but be careful and know what youre doing or youll get a good shock. So, if coil is good and you have voltage on it, it will still not fire the coil till the points close and conduct then open. Also, did you take the coil wire from the coils output (pull it out of distributor) and place it near ground and crank to see of at least the coils firing?? All the distributor does is use the rotor and cap to direct that spark to the right plug. You dont need a distributor or rotor or cap to see if the points are firing the coil to ground. Good Luck John Nordhoff aka Old John T in Indiana jmn50@msn.com
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