This is a pretty straight forward mod. I replaced all wire from the relay to the lights, the ground wires, and the power wires with 10 guage fine strand. Here is the final wiring diagram for a 1990 K5. Not sure if prior years are the same, but years after should be. This mod really makes the factory headlights much brighter. This is due to connecting directly to the alternator or battery through the relays and not going through the high guage (low amperage) factory wire.