Cutlass Ciera FWD L4-151 2.5L (1982)
Radiator Cooling Fan Motor: Description and Operation
On models equipped with electric engine cooling fans, the battery ground cable should be disconnected whenever underhood service is performed.
1982---84 GM FRONT WHEEL DRIVE MODELS EQUIPPED WITH TRANSVERSE MOUNTED ENGINES
DESCRIPTION
The single speed electric cooling fan is used on all models except those equipped with V6 gasoline engines with heavy duty cooling systems and all
diesel engines, which use a two-speed electric motor. The fan motor is operated by the cooling fan relay on single speed models or cooling fan relay and
cooling fan speed control on two speed models. On single speed models, when coolant temperature exceeds 230 degrees F, the cooling fan temperature
switch closes. On two-speed models, when the coolant temperature reaches approximately 226 (diesel 223) degrees F, the low speed cooling fan
temperature switch closes, and at approximately 239 (diesel 246) degrees F, the high speed cooling fan temperature switch closes. On all models, when
the cooling fan temperature switch closes on single speed models, or the low speed cooling fan temperature switch closes on two speed models, it allows
current to pass through the fuse and cooling fan relay coil to ground, thus closing the relay contacts. On single speed models, when the relay contacts are
closed, current flows through a fusible link to the fan motor. On two speed models when the relay contacts are closed, current flows through a fusible
link, then cooling fan speed control low speed contacts, and into the fan motor. On two speed models, when the high speed cooling fan temperature
switch closes, the solid state circuitry of the cooling fan speed control is grounded, causing cooling fan speed control high speed contacts to close and
cooling fan motor to operate at high speed. On single speed models, when coolant temperature falls below a predetermined level, the cooling fan
temperature switch opens and current is no longer supplied to the fan motor. On two speed models, when coolant temperature falls below the high speed
cooling fan temperature switch predetermined level, the contacts open, opening the ground circuit to the cooling fan speed control and causing the fan
motor to operate at low speed. When the coolant temperature falls below the low speed cooling fan temperature switch predetermined level, the contacts
open, causing the cooling fan relay to open and shut off current to the cooling fan speed control and the cooling fan motor. On 1982---85 diesel engine
models with A/C, a second switch (diesel engine models use two switches) which senses compressor head pressure to the condenser, is used to activate
the fan motor when the A/C compressor is operating. On all other models equipped with A/C, the cooling fan relay is grounded whenever the A/C
selector switch is in the Max., Normal or Bi-Level position, causing the cooling fan to operate. On some automatic transmission models with gasoline V6
engines, the electric engine cooling fan operates when the torque converter clutch is engaged.
TROUBLESHOOTING
1.
If coolant fan motor does not operate, check the following:
a. Check for blown fuse.
b. Check fusible link.
c. Disconnect wire connector from engine coolant temperature switch. With ignition ``On,'' ground end of wire. Fan motor should operate.
2.
If cooling fan operates whenever the ignition switch is in the Run position, check the following:
a. Check cooling fan temperature switch, compressor pressure switch, if equipped and other related mechanical components.
b. Check cooling fan relay.
FAN MOTOR, REPLACE
1.
Disconnect battery ground cable, then disconnect wire connector from fan motor.
2.
Detach front lamp wiring harness from fan motor, then remove harness from fan motor frame.
3.
Remove fan motor frame to radiator support attaching bolts, then remove fan motor.
4.
Reverse procedure to install. Torque fan to radiator support attaching bolts to 85 inch lbs.
