I'm posting here because I was recently troubleshooting an engine problem, which I ended up fixing, but while I was troubleshooting I decided to test the fuses and ran into some complications. First, the when I used the tester on the fuses in the underhood fuse/relay box, none of the fuses would light up the tester. I had the key in the run position, and all the fuses in the instrument panel fuse box tested fine, so I know its not the tool, but none of the ones in the underhood box would respond at all and I'm not sure why.

The second problem, is that there are a whole lot of fuse slots in the underhood box that show as being occupied on the diagram but don't actually have any fuses in them. Two of them, the Fuel Sol and Glow Plug, are for diesel only and this burb isn't diesel so that explains those two, but the slots for the BRAKE LAMP RELAY, the STOP/HAZ big fuse, and small fuses for DIODE I, AUX FAN, and the A.I.R. RELAY are all empty as well. Does anybody know what these slots are supposed to do and whether or not they are supposed to be empty? I have searched all over for this info and haven't managed to get an answer so far.

Anyways, thank you in advance for any help any of you can provide.
this is what my fuse box currently looks like

 

You have a generic fuse box as with all vehicles. Rather or not there should be a fuse, is dependent on if your vehicle has that option, i.e. rear window defoger.