2002 Lexus LS430 starts but nothing works

Hi,

I am trying to fix my brother's car, a 2002 ls430. I tested at the battery and only had
12.5 volts with the car running so I pulled the alternator but it tested good. The car will
start but there are no lights, radio, shifter won't come out of park, etc.  I was able to
just pull the cartridge fuse out without having to split the fuse box. It is marked on the
top cover as ALT 140 amp but after getting that fuse into the light it says 40 amp on
the top of it. Do you think someone has worked on this before he purchased it a couple
of months ago and put the wrong fuse in it or is that how they are supposed to be
marked? My eyes aren't real good but the fuse doesn't have a big separation in it like
the manual shows a blown cartridge fuse is supposed to look like either but I'm not
sure where else to look for the problem. There are also some more fuses in that block
that aren't shown in the manual but it is the correct manual they are also not shown on
the lid of the fuse box. Also, the car wouldn't start until I replaced a 10 amp blade fuse
marked INJ, it would crank but wouldn't start so I think that was something to do with
the injectors if that helps. Thanks for your time.