OK, got smart on it. Yes it has a day tank. And FL1/FL2 float. And 3 way valve. Pull out the float switch. It may have one, or two black floats on it. Check it with a multimeter. Pins A&B should be FL2 and C&D should be FL1.
f. Day Tank. The day tank has a fuel capacity to
permit engine operation for a minimum of 5 minutes. It
provides a settling point for contaminants, to prevent
their entry into the engine, and supplies fuel to the
engine fuel pump. The tank contains a dual type float
switch. The upper float operates in conjunction with the
fuel solenoid valve L2 to maintain a predetermined fuel
level in the tank. The lower float initiates an engine
shutdown sequence in the event that the fuel level in the
tank will permit operation of the generator set, at rated
load, for only 1 minute.
5-59. FUEL LEVEL SWITCHES FL1 and FL2. The
following paragraphs provide inspection, test, service,
and replacement instructions for either of fuel level
switches FL1 or FL2 (figure 4-46).
b. Test.
(1) Remove electrical connector (1, figure 4-46)
from fuel level switch (10), then unscrew switch from
day tank (9).
(2) Support switch in vertical position (electrical
connector on top). Connect an ohmmeter between
connector pins C and D. Meter should indicate
continuity. Raise lower float to upper limit. Meter
should not indicate continuity.
(3) Connect ohmmeter between pins A and B.
Meter should indicate continuity. Raise upper float to
upper limit. Meter should not indicate continuity.
4) Replace fuel level switch (10) (if defective) then
connect electrical connector (1).