ignition to coil wiring 55 2nd gen - The 1947 - Present Chevrolet & GMC Truck Message Board Network

vjjack04 · 01-31-2015, 03:43 PM

Guys, my ignition just stopped firing and i think the my Pertromics Flamethrower III module may have gone bad. I have about 13 volts to coil and plugs dont show spark. When i flip the switch to on i have the same volts to the neg side of the coil, off nothing, like its supposed to be....the thing was running fine and all it does is turn over now. Oh the engine is a modified SBC. The neg side of the coil should have the green wire from the ignition.....right?

1project2many · 01-31-2015, 04:20 PM

The ignition system will provide ground to the coil and intermittently interrupt this ground to cause spark. It won't provide constant ground. A quick test to see if the ignition system is working is to connect one end of the light to positive side of the coil and one end to the negative terminal then crank the starter. If the light blinks evenly and regularly you know the system is trying to fire the coil. If that's the case you can check for spark at the distributor end of the coil wire, then on one or two plug wires to see if there's a problem on the secondary side.

01-31-2015, 03:43 PM	#1
vjjack04 Registered User Join Date: Jun 2010 Location: Bear Grass, NC Posts: 291	ignition to coil wiring 55 2nd gen Guys, my ignition just stopped firing and i think the my Pertromics Flamethrower III module may have gone bad. I have about 13 volts to coil and plugs dont show spark. When i flip the switch to on i have the same volts to the neg side of the coil, off nothing, like its supposed to be....the thing was running fine and all it does is turn over now. Oh the engine is a modified SBC. The neg side of the coil should have the green wire from the ignition.....right?

01-31-2015, 04:20 PM	#2
1project2many Registered User Join Date: Mar 2012 Location: Lakes Region NH Posts: 3,200	Re: ignition to coil wiring 55 2nd gen The ignition system will provide ground to the coil and intermittently interrupt this ground to cause spark. It won't provide constant ground. A quick test to see if the ignition system is working is to connect one end of the light to positive side of the coil and one end to the negative terminal then crank the starter. If the light blinks evenly and regularly you know the system is trying to fire the coil. If that's the case you can check for spark at the distributor end of the coil wire, then on one or two plug wires to see if there's a problem on the secondary side.



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