just a quick thing. On both wiring systems, there are only 4 wire that come from the wiper switch to the wiper motor in the 82 and 85.
those 4 main colors are pink, purple, dark green and gray. you should be able to find those coming in the 82 harness. Those are the primary ones to match up first.
now the main issue i see from looking at wiring diagrams, is that in 82 they ran 12v power to the motor first under the hood, and used the wiper switch to ground the circuit. However in 85 they used a reversed system, where the 12v power went through the switch and then grounded coming out the wiper motor.
im going to assume the multiple terminals for the 82 are becasue the washer fluid pump is seperate and i think by 85 it is integrated(theres actually a circuit board under that black cover) so the wiper motor/washer pump now only needed one connector.
im still tryign to work it out in my head, it'd so much easier if i could go into my garage and look at my 85 IROCs setup, but im in Afghanistan now, lol. But from what im seeing so far. you'd need to connect those 4 main wires i mentioned before, then find the white wire that would go to the original 82 wiper motor, that engine compartment section wont be used....
stay with me now(im gonna ramble because im thinkign as im typing and ill be correcting myself often i bet, sorry)... the 82 switch is probably a common ground setup, using that one ground for other things, possibly directionals highbeams etc... I was goign to say find that ground and connect the white wire to it, thatd work if it wasnt a common ground, but i bet it is, so dont do that. lol. basically what you need to do is run power to that switch on the column. from the wiring schematics im lookign at it seems the wiper switch should have its own ground and not tied into any other system. can you tell me if in 82 the wiper switch is even on the column? lol. essentially what you wanna do it take the white wire coming from the 25a fuse for the wipers and run it to the ground wire(once un-grounded) of the wiper switch IF THE WIPER SWITCH IS ISOLATED
ONLY. that youd have to check to make sure. and thats means as in no other wires are there. im probably being confusing. huh? lol. im sure im overcomplicating it now. when the wires are hooked up, now 12v power will run from the fuse to the switch, through those 4 main colored wires, and to the 85 motor assembly, which should also have its own ground of some sort, possibly through the mounting legs themselves if nothign else. Another route would be to use a 85 wiper switch and color match the wires to that, 4 main one, and then the white from fuse box to the white on an original 85 pigtail for the wiper switch.... thats about all i can tell ya for now, and i apologize again if i confused you even more.
check out the diagrams and youll see how the +/- systems are reversed in the 2 years.
82 wiring...
http://www.austinthirdgen.org/mkport...ody_wiring.gif ---one with wiper
http://www.austinthirdgen.org/mkport..._continued.gif
85 wiring...
http://www.austinthirdgen.org/mkport...ody_wiring.gif
http://www.austinthirdgen.org/mkport..._continued.gif ---one with wiper