Draining Holding Tank - GMC 1975 Motorhome Operating Manual

SOLUTION :
4. PROBLEM:
CAUSE:
SOLUTION :
5 . PROBLEM:
Dumping Station Connection
a. The black wire is positive (hot) and the
white wire is negative (ground) .
b. Recharge auxiliary (living area) battery.
c. Branch wire should be #14 gauge mini-
mum.
d. Replace timer assembly.
Flushing action is weak or noisy.
a. Pump is running backwards (reversed
wiring polarity) .
b. Cycling unit without enough charge water .
c. Pump damaged by continuous dry opera-
tion .
a. The black wire is positive (hot) and the
white wire is negative (ground) .
b. Charge to proper level (3 gallons) . Fill to
charge level (c) on indicator lens.
c. Replace pump assembly.
Lack of capacity .
CAUSE:
Too much charge water.
88
Opening Holding Tank Control Valve
SOLUTION :
Use three gallons only to charge . Fill
to
charge level (c) on indicator lens.
DRAINING HOLDING TANK
NOTE :
If holding tank is allowed to overfill,
the overflow will back up through the bathroom
shower drain.
1 . Be sure the holding tank valve is closed .
It is located on the left-hand side of the vehicle
just behind the left rear tandem tire.
2 . Remove dump hose extension from the
storage tube inside rear bumper.
3. Disconnect dump tube retaining strap
mounted to center of rear crossmember. Remove
dust cap from pump tube.
4. Join dump tube extension to dump hose
by rotating adapter clockwise.
5. Put end of dump hose extension into sani-
tary dumping station opening. Make sure there
are no sags in hose as this would prevent com-
plete dumping.
6. Release two snap retainers at the control
valve and pull handle straight out to open. This
will drain holding tank completely.
NOTE :
If you are using a sewer hook-up in a
RV park keep the valve closed until you leave
or the holding tank becomes full. This will allow
solids to drain more readily.
7. After the holding tank is empty, it is rec-
ommended that the control valve be closed and
several gallons of water be added to tank