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UNDERSTANDING YOUR INSTRUMENT PANEL 115
4
Residual Engine Heat Utilization (REST)
The REST switch (1) is located on the
center section of the dashboard.
The residual engine heat utilization
system can be used to keep the
vehicle interior warm for some time
after the engine is switched off.
Turn the key to position 0 in the ignition lock or
remove it altogether.
To switch on:
1. Press the residual engine heat utilization switch (1),
the indicator lamp (2) lights up.
The blower will run at speed 1 regardless of the
setting of the airflow control.
2. Set the temperature control as required, refer to
"Heating, Ventilation".
To switch off:
Press the residual engine heat utilization switch (1)
again, the indicator lamp (2) goes out.The residual engine heat utilization is automatically
switched off if:
1. If the key is turned to position 2 in the ignition lock,
2. after about 30 minutes,
3. if the battery voltage is too low.
A IR CONDITIONING, REGULA TED (OPTIONA L)
The air conditioning switch (1) is
located on the center section of the
dashboard.
The air conditioning can be used to
cool or dehumidify the air in the
vehicle. The selected temperature is
reached as quickly as possible and
then held constant.
The air conditioning is only operational when the
engine is running.
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Page 122 of 272

122 UNDERSTANDING YOUR INSTRUMENT PANELHEA TER BOOSTER
The switch (1) for activating the
heater booster system is located in
the center section of the dashboard.
The heater booster system can be
switched on while the vehicle is
being driven to help the engine to
reach its normal operating
temperature more quickly, which
will help to heat up the passenger compartment as
quickly as possible when the heating is switched on.To switch on with the engine running:
Press switch (1), the indicator lamp (2) lights up.
To switch off:
Press switch (1) again or switch the engine off. The
heater booster will then switch to run-on mode (about
2minutes).
NOTE: When the vehicle is being driven and a coolant
temperature of over 185 °F (+80 °C) is reached, the
heater booster system will switch to regulation mode.
If the coolant temperature drops to below 167 °F
(+75 °C) with the heater booster system switched on,
heat output is increased again.
If the key is turned to position 0 in the ignition lock
(run-on for about 2 minutes), the last setting selected at
switch (1) is retained when the engine is restarted
(memory function).
The operation of the heater booster system is usually
not required at outside temperatures above 41 °F
(+5 °C).
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Page 137 of 272
STARTING AND OPERATING 137
5
Constant RPMs (Optional)The switch for the Constant RPMs
is located on the center section of
the dashboard.
Constant RPMs increases the
engine-idling RPMs to a set
working-RPM level and maintains
this level regardless of work load.
It can only be used when the vehicle is stationary, the
parking brake is engaged and the gear selector level is
in position "P".
Constant RPMs indicator lamp
To switch it on:
Press the top of the switch; the indicator lamp in the
switch and the constant RPMs indicator lamp
will light up.
To switch off
Press bottom of switch.
Freightliner-all.book Pag e 137 Monday, December 1, 2003 2:54 PM