R/V Series Auxiliary Heater; Description - GMC G Service Manual

1A-14 HEATING

R/V SERIES AUXILIARY HEATER

DESCRIPTION

An auxiliary heater provides additional heating capacity
for the rear of the Suburban model.
This unit operates independently of the standard heater,
and is regulated through its own controls at the instrument
panel.
This system consists of a separate core and fan unit
mounted in the rear of the vehicle.
Heater hoses extend from the unit to the front of the
vehicle where they are connected to the standard heater
hoses with "tees." An "on-off" vacuum operated valve is
installed in the heater core inlet line in the engine compart­
ment. This valve cuts off coolant flow to the auxiliary core
during warm weather and eliminates radiant heat
(figure 17).
Two control methods are used:
COOLANT-CONTROL VALVE
When heat is desired, and the blower switch is any posi­
tion except off, a vacuum operated valve controlled by the
switch, opens the coolant line to permit hot coolant circula­
tion through the heater core. In the OFF position the valve
is closed to prevent unwanted heat.
BLOWER SWITCH
The three-speed blower switch is located in the instru­
ment panel to the right of the steering column.