Holiday imperial 2001, Owner'S Manual, Page: 215 / 301

A majority of the lighting and appliances are designed to operate from
12 Volt DC (direct current) power. This is why the batteries play such an
important role in the function of the motorhome. There are exceptions with
appliances such as the microwave or television; however, indirectly they still
operate from 12 Volt DC power, as they can be operated from the inverter. The
chassis functions (engine, transmission, dash air, etc.) are also 12 Volt DC.
With the all technological advancements taking place in the past several
years manufacturers have now incorporated electronics into these systems. It is
important to keep the 12 Volt system(s) in good working order. These
systems, with their incorporated electronics, are voltage sensitive. Some items
can be damaged if the DC voltage is not maintained within the designed
specifications.
There are two separate 12 Volt systems. One is the chassis system; the
other is the house system. These two systems, for the most part, are separate
from one another. The house system does not operate engine functions; as the
engine system does not operate house functions. However, within the two sys-
tems there are some inner connections. For example: While the motorhome is
driven the alternator on the engine will charge the house batteries. Likewise,
while the motorhome is plugged into shore power or the generator is running
the engine battery(s) are being charged. Each system will supply 12 Volt DC
power to the 12 Volt distribution panels. The 12 Volt panel that services a
majority of the chassis system functions is located outside by the driver’s front
wheel. The other panel, located in the bedroom, services the house interior
functions such as the interior lighting and appliances. You should become
familiar with these panels and the items they operate.
The two different systems, engine and house, have their own set(s) of
battery(s). The engine battery supplies 12 Volt DC power to the front distribu-
tion panel located in an outside compartment by the driver’s side front wheel.
This panel contains mostly engine system fuses and wiring such as headlights,
taillight, dashboard functions, gauges, etc. The house battery(s) supplies
12 Volt DC power to the distribution panel located in the bedroom. This panel
contains fuses for the house, interior lighting and appliances, such as the
furnace and water heater.
The main battery disconnect for the chassis battery turns the DC power on
or off to the rear and front run boxes. Most chassis and engine functions are
interrupted when the battery disconnect is turned off. Some electronic items
require a constant power source for memory retention such as the dash and
CB radios. Some electronic components of the engine and transmission require
a constant power source. Turn the main battery disconnect switch off when the
motorhome is going to be stored or performing electrical maintenance. If pos-
sible, leave the motorhome plugged into an AC source with the battery discon-
Electrical Systems - Chassis
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I M P E R I A L 9 • 2 1 5
INTRODUCTION
BATTERY
DISCONNECT
- CHASSIS