Howdy All,

My car had been switched to HEI (before I got it) and today I just changed the ignition module for the second time in 3 months. Seems kind of strange to me. Does anyone have any ideas as to what might be causing this or do you think that the last module was faulty.

Are you running the HEI off the old resistance wire? Usually you would think that lower voltage might make for lower stress. But it's possible that running an HEI module off of a current limited source could cause the failure. For one thing, the positive voltage terminal will be able to ring more than it would without a resistance wire or ballast wire feeding it.

If the resistance wire isn't the golden bullet then I'd start to ask questions about the coil. If the coil is after market then it's possible that it is not well suited for the module.

I believe I was told that NAPA sells a GM ignition module replacement that is a bit heavier duty that stock.

One last thought. If your system voltage isn't regulated well enough, the ignition module may suffer. MSD is one such supplier that is very peticular about the system voltage. That is one reason whey internally regulated alternators are so popular - they do a much better job than the old buzzer box regulator.

And along with dnult's suggestions, I'll add to place some of the dielectric grease across the bottom of the module to transfer heat to the dist body.

If resistance wire is still being used, replace it with #12 AWG from the firewall plug, or run a new wire from the IGN post at the fuse box.

Good point about the grease everett. The grease is known as silicon grease or heat-sink-compound. Last I checked Radio Shack carries small tubes of it. Don't confuse it with dielectric grease that you find in many autoparts stores. Dielectric grease is a protectant for electrical connections. The grease everett is talking about conducts heat well, but does not conduct electricity.

Something that I used to see a lot at my garage was that people would swap the distributor cap out and not swap the ground strap from the old cap to the new one.

Make sure that the metal ground strap that makes up the center terminal of the HEI connector on the cap and grounds the metal frame of the coil is there, and if not go to any Standard Motor Parts dealer and have them get you one. They come in a box of 5 for about $6. I used to keep a box around for just such cases.

The ignition will still work but it will kill the module every couple of weeks w/o this ground strap.

Paul D.