1964 malibu wagon..Where is the ground for the head lights? I have tail lights, dash, and dome/courtesy light.I have brand new lightswitch,dimmer switch. With a test light , I have power at battery, fuseblock, lightswitch,dimmerswitch and at headlight terminal plugs. On my '66 malibu there is a ground wire that comes out one of the headlight terminal plugs and grounds to the body, my '64 does not. How or where do the headlights get grounded ?

Should be exactlty the same as your 66 ! One end of the headlight loom at least should have a ground terminal soldered on, you've got three wires to both high-lows (outers) and two wires to the (inner) high beams right ? the black is ground on all of them.
so I guess the ground terminals are missing ?
dave