if you bought the harness for this truck
https://www.americanautowire.com/PDF...20IN%203.1.pdf
on sheet 2 the top right shows a pic of a purple split wire with connectors. that plugs into the neutral safety switch and connects to the 2 purple wires coming out of the main harness. (no splicing and no terminals to solder on)
the backup switch is #7 on that sheet and looks like you solder on connectors and an 'L' plastic piece. plug right into backup switch.
the brake switch #5 (is above the middle of the steering column. Way up there)
looks like this
https://www.partsgeek.com/assets/pro...0-MKMQXTM3.jpg
should not have to solder or splice anything. it should just clip on.
i could probably come by this weekend if you are still having trouble.