I bought a 1995 Chevy G20 recently. When I turn on the hi-beams, the low-beams turn off. Is this normal? Could it be a wiring problem? My dad thinks we have to buy a whole new set of lights to fix this. (We do need one new light, but he wants to replace all 4.) All of the lights, except one, turn on fine. I don't see why replacing the bulbs would fix the problem when the problem seems to be with the wiring. Any insight on this?