[VetteVet]

Originally Posted by franken

The tach output on the distributor is just that--an output. It means little as a test.
You need to check the 12V input to power the HEI.
If the engine cranks, you most likely don't have a ground problem.
So assuming 12V in, and no spark, best guess w/o pulling the cap is a bad module. Maybe the coil, but that's rare.
Simply ordering and shotgunning parts is a great way to waste money, and not much more. For some reason, people choose the most expensive part that's hardest to replace to swap for no reason. What did you choose?

Originally Posted by DHighway

Vettevet, I was told that run from negative on the battery to batt terminal on the distributor with key on should should light and be steady, for testing the control module, and positive on battery to the tach wire on the distributor cap and cranking engine should flash test light, and that test is for the control module. Now im confused did I mix up the procedure for those tests?

If you ground the Batt terminal on the distributor it will not let the coil charge regardless of what the pickup coil and the module are doing You need some sophisticated equipment to test the module and the pickup, forget the tach stuff until you get power to the batt terminal. You're getting some excellent advice here from Franken and the others, you should follow it first.