Im using add a circuits to wire my gauges into my driver fusebox, I used one of these to wire my radar detector which has relatively low voltage usage. For my Guages which require a 12v tap, Is there any certain fuse location these should be plugged into, or any of the taps should suffice. Its been a while since ive worked with wiring electronics.. Considering the Device is running relatively low current and low resistance, any tap location should work if im not mistaken?

 

You can tap off before or after the fuse. If you tap off after the fuse, know that the circuit you're tapping is that much closer to the fuse rating whenever there's a spike. Your best bet is to tap off BEFORE the fuse and then add your own fuse to your new gauge circuit.

This way you have protection for your gauges and not interfering with the circuit you're tapping into. ATO also makes fuse blocks that hold automotive fuses just like that. Someone else wrote up a little thing about adding a terminal block to connect multiple gauges to a single tap of light signal (to dim gauges), ACC power and constant battery power. ATO's fuse block (4, 6, 8 and 10 fuse available) would do the same thing except throw a fuse in there.

I'm waiting on this in the mail:

To do exactly this... using fuse taps like your Add-a-Circuit thing.

Edit: That Add-A-Circuit is already fused for your application, no need for an additional fuse block. One slot is for the factory fuse to go back into its original circuit and the other is to fuse your gauges. And as for where to tap off, any ACC fuse will do the trick.