HERCULES.1
Both the dual fuse block and the grounding block were mounted inside
the cooling outlet plenum inside the back of the amp after removing
the fly screen blocking free flow of cooling air.  I asked TenTec the
purpose of this fly screen and they said "To keep the bugs out!".
This flyscreen looked like a great place for dust to collect cutting
off the airflow to cool the amp so it was removed.  The plenum is easy
to remove by unscrewing the sheet metal screws.  Use a wood block to
drill and mount the blocks as the aluminum is real thin and distorts
easily.  Mounting the blocks in the plenum eliminates possiblility
of damage to them as they are now inside the amplifier case.  The
#4 power cables are run through the outlet holes and terminated in
soldered on terminal lugs made for them. (Gold plated, of course!)

Fine strand #8 wires were run from positive and negative terminals of
each of the 4 amplifiers to the centrally located control board and
from the control board to the blocks in the plenum through 2 existing
holes in the chassis just in front of the plenum.  The wires were
soldered directly to the original lugs which are riveted to the boards.
I found 5 of the rivets on the boards loose from initial inspection
and soldered them down properly to the board foils.  The solder had
evidently broken loose when the factory pushed the cables onto the
tabs.

My mobile uses twin 1000 CCA deep-cycle marine batteries in parallel
with #0 welding cables.  One battery is next to my old Mercedes
diesel engine in the engine compartment and the other is inside the
car in the biggest battery box I could find next to the amp.  Under
full load, at 600 watts output, there is no appreciable voltage drop
on the Hercules II front panel voltmeter below battery voltage.
Before the modification, voltage dropped a good 1.5 to 2 volts below
what the battery measured under load.  Only the voltage drop across
the .015 ohm fusisters TenTec uses instead of a proper fuse and for
balance input to the protection circuit is evident.

Using a 14' long homebrew Bugcatcher with Henry Allen's biggest
6" diam coil, I am getting consistent 20 to 40 over S9 on 80/40/20
meter phone, packet, rtty and Pactor.  Amazing mobile...

73, Larry KN4IM-12 mobile!