Let me see if I can help you with this:
I had the same issues with "toasty wiring"...specifically the ones you are talking about. The previous owner apparently tried to fix this haphazardly with electrical tape, but a lot of bare wire remained.
I went to the dealership parts dept, and was told that they only sold the main harness, not the anciallary one.
So guess what? I ended up MAKING one!
I have several rolls of automotive wire and heat shrink tubing.
After I completely removed the offending harness from the engine compartment, I took it in the house and measured off same length wiring of the same colors and made new wiring, and spliced the original connectors onto the new wiring.
Now the original was actually same color insulation with different color stripes (can't find that anywhere), so I just used wires with the same color insulation to easily identify what went with what.
Upon reinstallation, everything worked...except the oil pressure gauge, which just pegged at the "3" position. I had to replace the oil pressure sender a week later and it works fine now.
I will say this. There are three wires in the harness. One is for the starter solenoid, the other two are for the oil level sensor and the oil pressure sender.
Until you get that harness rejuvinated, your indicators aren't going to work very well (or not at all.
Hope this helps.