Help with HEI

[Alaska71SWB]

I have a HEI in my 72 plow truck. Its been burning the electonic ignition modules. On the last module NAPA tested it and said both the high and low rpm was bad. At first I thought it was just a bad module but after 3 ingnition modules in 6 months, the last one only lasting 1 month I think there must be something else going on. Anyone have any ideas for me.

[Rooster's 67]

have you been using the dielectric grease that comes with the module to help heat transfer to the dist housing?

[Rooster's 67]

also check the power for excessivly high voltage and you may check the coil primary winding for low resistance the module triggers the coil on the ground side.

primary winding should be about 1.5-3.0 ohms resistance if memory serves.

[Alaska71SWB]

Thanks for the help. I have been using the grease but I haven't checked the voltages. I will do that next.

[Tx Firefighter]

Rooster is on the right track. The coil can be the culprit.

Also, there is a huge difference in module quality among the different brands. AC Delco is the best choice.

[Huck]

I would swap out the coil and the condenser at the same time with the module. Make sure your grounds are real good ---block to firewall---and also make sure your ign wire to the dist is heavy enough--don't use the stock wire-upgrade a bit. If it still die's get another dist as it isn't worth the hassle----junk yard HEI go for $30.

[cdowns]

if you're using the stock factory wire to the distributor that could be your problem the stock wire is a resistance wire and delivers only 9volts or so to the coil