[MARKDTN]

You can get them on Ebay or Amazon as a generic version. It might have have cheap relays and cheap connectors. It is called an "H4 headlight relay harness" or similar. I have made my own, but it's really a pain to get all the connectors you need and good relays. I have bought cheap harnesses and upgraded the relays to Hella or Bosch as the 5 pin relays are pretty common.

There are at least 4 versions of this type harness. 1-1 relay just for both low beams, 2-2 relays (1 each low beam), 3-2 relays (1 for high beams and 1 for low beams), or 4-4 relays (2 for high beams and 2 for low beams). Variation 1 and 3 are the most popular that I have seen.

I bought one of these version 3 for my sons '97 Blazer and it made a lot of difference at night. Without changing bulbs it was a noticeable difference in light output-and it takes the load off the headlight switch.