Radiator fan
Radiator fan refers to the electric cooling fan used at the front radiator of the Pontiac Fiero.
The radiator fan helps pull air through the radiator when vehicle speed or natural airflow is not enough to keep coolant temperature under control.
Overview
The Fiero radiator is mounted at the front of the car, while the engine is mounted behind the passenger compartment.
Because of this layout, the cooling system uses long coolant pipes between the engine and the front radiator. The radiator fan is mounted at the radiator and is used to increase airflow through the radiator when needed.
A radiator fan problem can cause overheating, especially at idle, in traffic, or at low vehicle speed.
Location
Image wanted: Photo or diagram showing the Fiero radiator fan location at the front radiator, plus fan relay and fan switch locations if possible.
The radiator fan is mounted at the front radiator.
The radiator itself is located at the front of the car, behind the front fascia area.
The fan is part of the front cooling-system assembly, not the engine-compartment assembly.
Function
The radiator fan moves air through the radiator when airflow from vehicle movement is not enough.
The fan is especially important during:
- Idle
- Slow traffic
- Hot weather
- Extended low-speed driving
- Air-conditioning use, if equipped
- Cooling-system diagnosis
Fan control
Radiator fan control depends on year and equipment.
The fan may be turned on by a temperature switch, ECM control, air-conditioning request, relay circuit, or related wiring depending on the model year and configuration.
Because fan-control details can vary, diagnosis should use the correct wiring diagram and service information for the specific car.
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Common symptoms
Possible radiator-fan-related symptoms include:
- Engine overheats at idle
- Engine overheats in traffic
- Temperature drops when driving faster
- Fan never turns on
- Fan runs constantly
- Fan works only with air conditioning
- Fan fuse or relay problem
- Intermittent overheating
- Temperature gauge rises while stationary
Common causes
Common causes of radiator fan problems include:
- Failed fan motor
- Failed fan relay
- Faulty fan switch
- Wiring problem
- Poor connector contact
- Blown fuse
- Poor ground
- Air-conditioning control issue
- ECM or control-circuit issue, depending on year
- Previous wiring modifications
Diagnosis
Basic diagnostic checks include:
- Confirm whether the engine is actually overheating.
- Check coolant level and cooling-system condition.
- Check whether the fan turns freely.
- Check whether the fan runs when commanded or powered according to the correct test procedure.
- Check fan fuse and relay.
- Inspect fan wiring and connectors.
- Check fan ground.
- Check the fan switch or control circuit.
- Check whether the fan operates with air conditioning if equipped.
- Check the correct wiring diagram for the year and configuration.
Relationship to overheating
A radiator fan problem often shows up most clearly when the car is stopped or moving slowly.
If the car cools normally at road speed but overheats at idle or in traffic, the radiator fan system should be checked.
However, overheating can also be caused by trapped air, low coolant, crushed coolant pipes, radiator problems, thermostat problems, water pump problems, or incorrect caps.
Related topics:
Air conditioning relationship
On many cars, the radiator fan may run when the air conditioning is turned on.
If the fan works with air conditioning but not from temperature control, the fan motor and some wiring may be functional, while the temperature switch or control side still needs diagnosis.
Notes
Do not assume the radiator fan is working just because the engine overheats slowly rather than immediately.
The fan should be tested directly if overheating occurs at idle, in traffic, or during low-speed operation.
Also do not assume every overheating problem is caused by the fan. The Fiero cooling system must be properly filled and free of trapped air.