http://terminalsupplyco.com/Store/Product.aspx?pc=TYR-005-1240

I use the SPST relays. You get two output terminals so each bulb gets it's own direct power feed( twin terminals 87 normally open). No need to splice the lines. I used one for the low beam and two for the hi beams in my 4 lamp system. About $14 per relay IIRC. Terminal Supply has the connectors and terminals also. They have a $20 minimum order policy so get the order right before you finalize.

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