I have a small problem that needs some advice. Recently my jacks (HWC) would not retract because no power was going to the switch. I opened the 12 volt fuse box under the dash to try and troubleshoo...
I am assuming you have empty fuse holders and trying to figure out if one of them should be active.
The problem you will have is if the circuit has a missing fuse and there is a switch in line and the switch is "off" then your test would not work.
On a fuse block (usually) all the fuses are connected to the 12V on the same side and the load side will be individually connected to a wire that goes somewhere and the non used fuse slots will not have a wire connected.