My 1970 cuda converted to electronic ignition . I bought an MSD 6A ignition box. Everything works except when I rev the engine all the lights flicker and the aftermarket voltage gauge jumps a volt. I temped in a jumper from the battery to the blue ignition field on the alternator and the flickering stopped. I also completely unhooked the connector to the voltage regulator and the flickering stopped. I also used a total of 3 voltage regulators and all flickered lights. Voltage regulator has an external ground wire run from the regulator to the engine block.Any ideas?
