Description: Two different types of
cooling fans may be used for the cooling system. Traditionally, cars
have used belt-driven, mechanical fans using the engine to turn
them. Mechanical fans are still used on some cars and light trucks.
These fans now use a temperature-sensitive fan clutch that allows
the fan to disengage and engage according to different operating
conditions. Electric cooling fans began to emerge around 1980 and
only come on when needed. The evolution from mechanical fans to
electric fans arose from sideways-mounted (transverse) engines and
transmissions, and the need to reduce
weight while increasing fuel economy. Some vehicles may use multiple electric fans
for better control of the cooling system.
Today’s cars use electric
cooling fans controlled by the same computer that
controls the engine.
Purpose: The cooling fan circulates
air through the radiator so it can release engine heat into the
surrounding air. With the introduction of fan clutches and electric
cooling fans, fans have become more efficient by operating only when
they need to. Electric cooling fans also improve the operation of
the air conditioning system. When traveling down the road, usually
at roads speeds above 30 mph, mechanical fans basically freewheel
and electric fans stay off. Air passing through the radiator because
of vehicle movement
is all that’s needed to ensure heat
exchange.
Maintenance Tips/Suggestions: A fan that does not provide sufficient
circulation usually causes overheating and poor air conditioning
operation. A fan that stays engaged at all times can cause poor fuel
economy, unwanted noise and may run the battery dead (electric fans
with A/C off). First, inspect the area around the radiator to make
sure it’s free of leaves and other debris. On cars with mechanical
fans, turn the engine off and check to make sure the
fan is intact and that the
drive belt
is
tight. On cars with electric fans, check your owner’s manual to determine
what fuses and relays may be involved in controlling the
fan. Replace any bad fuses and make
sure that the cooling fan relay is properly seated in
its socket. Beyond that, if you suspect
a problem with your car’s fan, have it inspected right
away by a professional service technician.
