GM 4-Pin HEI Electronic Ignition Control Module Wiring GM 4-Pin HEI Electronic Ignition Control Module Wiring Connections/Diagram with a Magnetic Pickup Coil. This electronic ignition system operates with full 12 volts. It is recommended only for ordinary lawn & garden equipment. HEI Distributor Conversion - Ray's Chevy Restoration Site Wiring for Conversion to HEI Ignition System: Another important issue is the combination of voltage regulator and HEI module that you are using. If you have a mechanical regulator (stock on pre-71), you may have problems with burnt out HEI modules.