Hei Coil burnt x 2

[neto]

Would a lack of grounds burn a coil? It rained today and was wondering if I lost ground somewhere? Does any one know where to ground and what to ground besides everything? 73 truck, converted to hei, was running fine till this morning when it wouldn't start. I check all connections and turned out to be the coil. I replaced the coil and it started right up. Moved it a bit then started it once more and that's all she wrote. I have another coil but don't want to put it in yet until I figure what happened.
Thanks.

[Tony@AirRideTech]

yes it can.....

[James McClure]

neto, check and see if the "coil grounding tab" is still in the cap or if it fell out or was discarded by accident. If tab is missing, get one from NAPA or just ground the coil with a wire, jim

[seanconnery]

yeah, the coil grounding tab can be tricky to keep in its place when replacing the coil. one of the 4 coil screws that fasten the coil to the distributor cap itself actually holds that tab and provides a ground as well. so theoretically, you could have your ground wire with the spade terminal connector hooked up to the coil grounding tab properly, but if the grounding tab isn't being held by that screw, you'll get nothing and scratch your head too. i've been there. when you replace the coil, before you hook up the spade terminal ground, turn the ignition on and check for voltage with a multimeter. if you get voltage, then the grounding tab is properly seated in the distributor cap and you should be golden. hope this helps.

Also, if you've upgraded to something like one of those ACCEL super coils and you're still using the factory HEI module, it will work for a few starts, then the ACCEL coil will fry the module. That has also happened to me. Either use all factory parts, or all ACCEL parts. you cant mix aftermarket coils and stock modules. again, hope this helps.

[Pyrotechnic]

You did remove the resistance wire for the points distributor right ?

[old Rusty C10]

for the fun of it if a coil is from an aftermarket manufacturer i have seen them do that right off the shelf due to manufacturing defects.. KEM was bad like that

[powerdriver 1958]

Sometimes left out is this metal ground tab

Should look like this in the cap

I try to put the ground wire over the ground tab and if its rusty like this.It needs cleaned up

HEI runs on full 12 volts, No resistor wire at all

[neto]

You guys are amazing!!! OK 2 more questions. Should the 12 volt wire for the coil have continuity to those two areas in the fuse box. Checking to see if a hot wire is grounding which might burn my coil. Continuity checked with battery completely disconnected all fuses out except for the horn. I have cleaned existing ground wires and put two more from block to frame. Changed the altenator clip, put a new coil. The resister wire is gone all the way to the firewall block. The ground wire is on as well as the ground tab. The second question is where the coil goes into. The second picture is how I put the probe then the rubber part with the spring through the hole and finally the coil but in another post I saw that I had it backwards. It should be the rubber first then the probe but seems like it doesn't protrude to touch the metal plate on the rotor. Which way should it be?
Thanks again.
Ernest

[neto]

Well went to pick a part this morning and took apart two hei coil setups to check for what goes in first. First the probe then rubber and finally the coil.
Thanks.