Ignition Control to Distributor

Bewy said
As a matter of interest, I have the cct diagram of the GM HEI 4 pin ign module.
Neither p/up wire is grounded, & as I stated above I doubt the Mopar one is either.

Although the back plate of the GM HEI module is grounded to the distributor (or mounting plate).

Same with the Mopar brain boxes, their steel casings must be grounded or it will not run. (hang one in mid air with the wires attached and try and start the engine, it's a no go.)