Guys, seems like I'm on here weekly looking for advice but it's only because I trust yours. Looking to do some initial basic wiring. More complete setup will follow (if I live that long - lol). I have a fuse block using minis and a jumper block (no fuses). I'll list the items that will need to be hooked up at this point. Question - after reading my list can you give me your opinions on which ones should be fused and the #amp fuse to be used and ones not needing to be fused? Tach Elec Radiator fan SunPro gauge set - Oil/Volt/Water Universal ignition switch Alternator (single wire) Fuel gauge Any I may have forgotten? Thanks guys.
I'd put all of the gauges on one circuit, fused at 10 amps. The fan, you'll need to know it's running current, size the fuse/wire to at least 150% of that number. I wouldn't fuse the alternator or the feed to the ignition switch, but would make sure the wire is large enough to prevent excessive voltage drop under 'normal' conditions. Do route the wires to prevent possible damage to them.
You might want to read this: https://www.jalopyjournal.com/forum/threads/wiring-101.843579/ Trying to build a harness piecemeal can cause major issues down the road, it's far better to have a pretty good idea of the final product before you start.
ditto on the "plan the whole thing first" advice. As Steve says in his 101 tutorial, fuses are there to protect the wire from getting too hot if there is a short circuit. you kind of need to understand how much current each wire is carrying, so you know what size wire to use, and what size fuse might be needed, where.
Do yourself a favour and read Crazy Steve's "Wiring 101" before you start. That thread is a tremendous resource, it's a great source of info even for those of us who are knowledgeable and experienced in automotive wiring. You'll find the answers to all your questions there.