Thread: burned coil

Tweet

I have a HEI ignition on an inline six cylinder and the coil was bad so I changed it and it started but only ran for about 3 seconds a stoped so I changed it again and it started back up for about 3 seconds and stoped. Why would it keep burning up the coil.

Could be a bad module? check for a white or yellow dot on the module...if you got one it's bad...

also and very important you have to have the ground strap or wire the grounds the coil if that is missing it can do the same...

I don't know what you are running but when they went from 6 volts to 12 volts in the 50"s . they added an ignition resistor either a ceramic block or a wire in the harness. In the start mode the coil was hooked to the 12 source for better spark, the starters would make measured voltage at the coil drop to about 10 volts instead of 14 that you would get measuring across the battery at the run position in non starting situations. the resistor dropped the measured voltagae to about 9 volts at run condition. if you are burning up coils you probably have a wrong or cross connedtion to the coil giving it 14 volts, i have seen coils explode when they are hooked up wrong and the car is just sitting there with 14 volts going to the coil. retired auto shop teacher, auto engineer

On an HEI I would guess you're not having coil problems but something else. First, check all the simple crap. Make sure all your wires are hooked up and in good condition, next make sure you have the ground strap in the cap with the coil. Also check the rubber grommet and button & spring under the coil in the top of the cap. If all this fails check the module, could be going bad or alraedy dead and the new coil, just gives it enough to fire for a second. Most parts stores will check the module for you. I rarely see HEI coils burn up, it's almost always another source and I wouldn't be surprised if you coils still work.