ok, its kinda crazy but try and follow. there is a plug coming from your harness on the frame rail that is red and has a connector like your o2 sensor has and on the other side of that plug is a black wire that goes into the black barrel thing on your neg wire. coming OUT of that black barrel thing which is the burnt-choped off-frayed wire you see, goes into a orange-redish wire near that read wire where this started. between the redish wire and that burnt chopped part was another plug like the o2 style that is obviously long gone due to what your seeing now.
if you notice you wont have any rad fans and this is the reason. i delt with this over the summer and came up with a fix that works perfect and powers up just as if it were still wired factory.
that 1 wire powers both fans and i found that lil wire gets hot as a merf when both fans are on and that is too much load for that lil wire so i divided up the load.
i got some 18 ga wire, a couple of eyelets, the correct plugs and made a re-drected power source. i ran the 2 wires from the pos bat post on the starter up to the 2 relays. i used the correct pin removal tool and yanked the orig terminal and replaced it with the wires running from the starter. one wire to each relay. i did this in orange so to be corretly color coded, loomed it, and threaded it neatly up to the relay area. seems like a lot but it should only take about 30 mins tops to swap things around.
the only diff is your not getting power from where ever the red wire connects to and bouncing back over to the relays, your getting it from the starter and dividing the power load. you shortend the distance the power has to travel.
noticed your in ark, what part? im just south of memphis 15 mins.
89 formula LB9 WS6 T-5
83 T/A 350 T-5
run it wide open till ya see god "THEN" brake !