Dodge 2007 Ram 2500 - Manual (Page 260)

• Voltmeter Operation:
• The voltmeter may show a gauge fluctuation if
certain engine temperatures are below 66°F (19°C).
This cycling operation is caused by the post-heat
cycle of the intake manifold heater system. The
number of cycles and the length of the cycling
operation is controlled by the engine control mod-
ule, this time will not exceed 150 seconds. The
needle should then stabilize at the approximate
operation point.
• The cycling action will cause temporary dimming of
the headlamps, interior lamps, and also a noticeable
reduction in blower motor speed.
Cold Weather Precautions
Operation in ambient temperature below 32°F (0°C) may
require special considerations. The following charts sug-
gest these options:
Fuel Operating Range
* No. 1 diesel fuel should only be used where extended
arctic conditions (-10°F/-23°C) exist.
260 STARTING AND OPERATING