I have a 1992 chevy c1500 silverado. When I flip my lights from dim to brights, why wont all 4 headlights shine together?
Because they aren't designed to. But with a little knowledge on how wiring works you can quite simply pick up 2 diodes from radio shack and about 6 inches of wire. Place the wire with the inline diode so it will pass the power from the high beam relays #87 terminal to the low beams 85 or 86 which ever is the side that recieves signal from the switch. And whichever side got that power wire to it needs to have the second diode placed on its wire so it won't back feed power to the switch.
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