AuroraGirl, thank you for taking the time to post all that. It helps. Here's what I'm doing to this '96 GMC I got recently: getting rid of the DRL's by pulling fuse 15 and removing the instrument indicator lamp, (DRL's did't work anyway). Getting rid of the composite headlights. Eventually may go with Daniel Stern Lighting's suggestions of W/T-single headlight front end, but not right now. (Would be best lighting option - not cheap) Have friend working in one local wrecking yard and get along well with second WY, so I can, "snip-and-******," working with them easily and I love wrecking yards. From them and a little luck, I picked up a set of glass 88/89 4-lamp LMC headlights. (36-0302 & 36-0303) I like the look so I'm using them. Will build my own HD harness and use factory headlight switch to trigger relays. Will use enclosure with 4 relay sockets; the 4th for future. I have a lot of wire, loom, etc., from 12ga. on down, so may as well use my own materials. That leaves only buying the required plugs/receptacles, etc. Which brings me to this post/thread I started. Your first photo of the black/brown/blue, "plug," (which I call female), is a dead ringer for the plug provided by LMC for their glass lamp enclosures with their bulbs. (But their wire is too small and I don't know how good their bulbs are) So to begin with, I need 4 of those same plugs suitable to accept 12ga. wire. You said the nomenclature for them is, "metrapack," so you have confirmed what I need to buy. Thank you! NOW, next I need at least 2 companion, "male," (the part with the shield or, "hood,") connectors to shove onto the headlight plugs presently hanging out of the front of my pickup. I'll wire up those to fire my new relays. To date the un-answered question is which side of the truck wiring/headlight plugs, to I use to fire the relays? I'm suspecting I only need one, "set," as that wiring would be multipled for both headlights. The wiring to activate the relays can be smaller than 12ga, even 18ga would work I think. Still, I will try to buy Delphi or American connectors as I don't trust Chinese. Lastly, I will need to figure adding the, "4-HI," option into my plan as otherwise I'll end up like the original 88/89 trucks where only 2 headlights were on at a time regardless of selecting high beam or low beam. Dumb GM idea there I think.
So my shopping list to do this now is: 2 metrapack 280 kits for 9005 lamp attachment; 2 metrapack 280 kits for 9006 lamp attachment; 2 companion male connectors to couple into truck's original headlight wiring, (I'll probably buy 4) - and relay stuff.
Finally, Donald, thank you for the link for the connectors; I looked and they are Chinese, so I'll probably continue looking, however, you've identified/confirmed the right parts.
