Sounds like a grounding issue? OR Maybe you have an exposed wire in the headlight harness touching another wire or touching the metal of the car. Something to check out.
2004 Nissan Titan Crew Cab
1966 Ford Mustang Original 289
Edelbrock RPM Performer Heads; bored .30 over
Weiand Stealth Intake, Holley 600 CFM Carb.
Comp Cam 268H 9.5:1 Speed Pro Pistons
Patriot Tri-Y Headers w/ 2.5" H Pipe, Flowmaster 40S
620 1" drop in front, CSRP Front Disk Brakes.
Ford 8 3.40 trac-loc rear end