My question is on a 67 Dodge Charger the headlight Motors when one headlight motor is running is it supposed to be putting power to both sides of the field on the other headlight motor I'm getting 9 volts on one side and 6 volts on the other side of the field doesn't matter which motor I use next question is the headlight motor supposed to be grounded out I can power the headlight motor either way without hooking a ground up to the three prong plug is that right