I’m not sure how you would do one wire at a time while continuing to drive the truck, unless you are willing to keep the substandard fuse layout though (or install several fuse blocks, one at a time)…. Also, in-line fuses are a nightmare when you have to troubleshoot something down the road- I would not recommend the in-line fuse route.
I’d like to hear ideas about upgrading the fuse setup while driving it and wiring it one wire at a time… this will be an interesting challenge.
I’ve only just begun to think about it, but the best thought I’ve had so far would be mounting the fuse block(s) and getting power distributed to it/them (redundant to the original setup)…..very early in this process. Then start connecting circuits to the fuse panel as I run the new wire to whichever system I’m working on.
A fair bit of forward planning will be necessary. And even then, things will be kind of clumsy with some rework and what not. I’m ok with that.
One of the first items I’d like to tackle, is new wire to the rear of the truck. I might actually do that BEFORE adding a fuse block. Just connect to the existing system and leave myself enough wire somewhere that I can reconfigure later as necessary.