Clean up the Black Ground Wires on the headlamp connectors. You indicate that you have voltage at the Beam Selector, and that you have replaced it.
So, that leaves either open power wires to the headlamps or grounds because the you indicate that the parking lights are functiona
The black wires on the headlight connectors splice into the ground wire for the parking lights. If the parking lights are good, and the Hi/Low beam selector switch have voltage on it, there is just a few things that it could be.
Eliminate the simplest things to check, then you will be left with the problem by elimination.
Joe Guilbeau<br />1983 Cherokee Laredo WT (SJ-17), 360/229/727/D44/D60 4.10 Gearing, 8-lug hubs, Edelbrock Performer w/EGR Intake, Mallory Unilite Series 47 Photo-Optic Infrared Trigger Vacuum Distributor, Mallory Surge Protector, Mallory Promaster Coil, Holley Pro-Jection TBI 502-Analog, FlowKooler High Output Water Pump, Staggered 4-Core Custom Industrial Radiator, HD Fan Clutch, Dual Electric Fans, CS130 Delco 105-Amp Alternator, Oil Bypass Mods at Rear of Block and Distributor Oiling, Superlift 4\" Suspension, Rancho RS5000\'s, Hi-Tech 31\" Re-Treads, Aero 33 Gal Tank w/Skid Plate, Custom Rear \"Longhorn\" Bumper