I need to know which wires go to which terminals on my light swit

The wires with large ends go to the battery post, the small purple wire goes to the terminal marked S.

how about the relay? The Lightswitch? Headlight ground wires? Igniton switch

Try this site www.alldatadiy.com

Right off the bat, I don't think you'll ever find a wiring diagram for taillights on two completely different makes of vehicles.

Best suggestion is to get a 12 volt test light and one by one check the wires going to the rear of you vehicle. Start by turning the parking lights on and then probing all the wires (one at a time) to see where voltage is present. Make a list of the colors of the wires associated with a particular action. Do the same for brake light, back up lights, and turn signals (both left and right).

Once you have established this base of info, start touching a wire (say, the left turn signal) to wires in your taillight assembly until you get the desired reaction in the Chevy taillight. Again, make a note of what combination of wires produces what result. Be patient and you can work your way thru this and get it to all function the way you want.

Got an 84 shop manual with wiring

What do you need ?

Also got a 1984 S10 Blazer since new

Go to google and type in 1984 Chevy K1500 wire diagram and one should come up.

Haynes repair manuals would have good wiring diagrams. Or google it, you can find about everything on the internet, but sometimes a problem with too small of print, or maybe my computer skills need sharpening.
I don't know about those wire connections not plugged in. Are you sure they are from the doors? Can't imagine what they would be.

Positive of one battery to hot of vehicle wiring harness--neg. of that battery to positive of other battery--negative of that battery to block (ground)

small wire with boot goes on the s stud for starter. need to buy relay from a better part store like napa

check the fuse and relay