Re-routing power for gauge

[Yolo78]

So I finally got a pyrometer installed (3 days before the head cracked anyway, go figure) … I suppose I’ll keep it. When the mechanic installed it he wired it directly to the battery. I prefer it to get power with ignition and am planning to jump an existing fuse. I figure I’ll use a spare in the main box, but I’m curious about the smaller box under hood. Can I connect to IG and ground to -E? I’m a newbie to auto wiring so feel free to educate me!! Any other upgrades a novice can do while it sits dead in my driveway waiting for my new 3L head?

 

[Dprio34]

@Yolo78 , Lots of people utilize the fuse panel in your 1st pic. If you already have an aftermarket radio, you may have or PO may have run a heavier gauge wire for that from the battery. You could also utilize that if you wanted to save a bit of time, and have to fish less wires. Either way, it will work.

 

[jblueridge]

If you use the engine compartment fuse box you will have to get the wire through the firewall and then to the gauge. Its completely doable but I’d use a fuse tap and keep all the wires in the cabin with you. fuse tap

 

[Yolo78]

If you use the engine compartment fuse box you will have to get the wire through the firewall and then to the gauge. Its completely doable but I’d use a fuse tap and keep all the wires in the cabin with you. fuse tap

Since the installing mechanic hooked it directly to the battery, the wire is already thru the firewall. If I connect to the small fuse box under the hood, do I connect to the IG stud or the IG fuse with fuse tap so it is fuse protected?

 

[jblueridge]

I believe the IG stud is powered through the middle fuse in that 3 fuse box.
Use test lamp or voltmeter to confirm.