My 1993 Pontiac Bonneville electric cooling fan doesn't come on. I believe that these fans should come on when temp is bet 180 and 200 deg. I also checked the fuse and is good, also took out fan and tested with car batt. and they work. Do you have any suggestions.

Its on the radiator

Using your tatco code reader, select current data (real-time data) and select engine coolant temp sensor (ECT). Run engine to operating temperature (A/C off). Monitor the temp reading - when the temp reaches approx 204 deg farenheit, the fans should kick on, after the temp drops to approx 198 deg farenheit, the fans should turn off. The fans are controled by the ECM (Engine Control Module). The ECM controls the cooling fan relays.

if your fans are electric check fuses and relay if they are good replace your coolant temp sensor that is what is most likely wrong anyway cheap at auto zone they are normally located right by thermostat housing or in the side of the block it tells your cars ecu when to cut on fans.

if your fan is belt driven replace you fan clutch and problem solved


if this helps you could you leave me good feedback thanks

Did you check for voltage at the fuses with key on? Use a test light, two fuses. Hope you can read diagram? trying to get everything I could in one diagram, a little small. Some makes and models, if you unplug coolant temp sensor, the fans will run all the time, it's a default feature. Not sure about your vehicle, you can try it?

I would check your relays first. Usually your problem is the relay. You may have a Service Engine Soon light on also. This can indicate that your coolant temperature sensor isn't working therefore the sensor isn't telling the computer to turn the fans on. Another quick easy test is to start the car and while it's idling either turn on the a/c full blast or the heater defroster. This should cause the fans to kick on for a length of time. (The length of time can very) If they do come on it would lead me to believe that you have a coolant temp sender problem. If they still don't come on after a few mins, I would definitely look into the relay.

Hi, check.........I need to know which fuse runs the cooling... on this forum thread. Its not a fuse if the fan turns but could be fan relay. Unplug the coolant temp sensor lovated just below the thermostat houing and see if the fans come on. If they do, it might be the coolant sensor that is bad.

Fan relay is below fusebox under hood in front of passenger. There are two. one high and one low cool

Fig. 1: The blower motor and fan assembly is mounted in the heater and A/C module, and is accessible from the engine compartment

GM Bonneville/Eighty Eight/LeSabre 1986-1999
Blower Motor - REMOVAL & INSTALLATION
(see Figures 1 and 2)

1. Disconnect the negative battery cable.
2. If necessary, tag and disconnect the number 2, 4 and 6 spark plug wires from the ignition coil and move the coil out of the way.
3. For 1993-99 vehicles, remove the nuts and cross brace bar.
4. Detach the electrical connections from the blower motor.
5. Disconnect the cooling tube from the blower motor.
6. Unfasten the screws securing the blower motor to the blower module assembly.
7. Remove the blower motor and fan assembly from the module.
8. If necessary, unfasten the nut attaching the fan to the blower motor shaft, then pull the fan from the blower motor.

Fig. 2: You can disassemble the fan from the motor by removing the retaining nut


To install:

1. If the fan was removed from the motor, position the fan on the shaft, then install the retaining nut. Tighten the nut to 12 inch lbs. (1.4 Nm).
2. Position the blower motor and fan assembly to the module, then install the retaining screws. Tighten to 5 inch lbs. (0.6 Nm).
3. Connect the cooling tube to the blower motor.
4. Attach the electrical connector to the blower motor.
5. On 1993-98 vehicles, install the cross brace bar and retaining nuts. Tighten the nuts to 18 ft. lbs. (25 Nm).
6. If removed, install the coil and connect the spark plug wires, as tagged during removal.
7. Connect the negative battery cable.

Hope this helped (remember rated and comment this).

There is a temp sending unit on the engine, it sends a signal to the engnie computer which provides a ground to turn on the fan relay. You might want to check the relay for the fan, I believe its on the passenger side just aft of the strut tower but dont quote me on that.

check the temp sender as this is what activates the fan