[HO455]

I would say it's going to be hard to make the wiring more basic than GM did originally. These are simple trucks with basic wiring. Yes they are more complicated than an Advanced Design truck but, they also came with turn signals, and electric wipers from the factory. With heaters, radios and dome lights as the few electrical options.

In addition I'm not sure I understand what you mean when you want to reduce the number of fuses. Reducing the number of fuses without reducing the number of circuits will increase the chances of a fire. Each conductor supplying power to a component needs to have a fuse that is sized to prevent the wire from melting if shorted.

If you have four 18 guage wires coming from a single fuse how do you select the proper sized fuse? If each wire is supplying a 10 amp load you would need a 40 amp fuse to handle the total load. Which would work until something goes wrong and the current draw on one wire rises to 18 amps. This would exceed the amp rating of the wire and it would overheat and the insulation would melt or burn.

I'll add one more thought. At some point you'll likely want to sell the truck, and an informed buyer will be turned off by a wiring harness with only one or two colors. Things fail and need to be repaired. Troubleshooting a system that isn't color coded is much harder and time consuming and if your having to pay for it expensive.

Good luck with your project! Building and installing your own wiring can be fun and educational. Do your homework and enjoy the trip.