Elements of the casing of the blower fan (Ford)
A - Blower fan
B - Fan resistor
C - Fan motor connector
D - Fan High Speed Relay
Blower Motor Resistor Test
Resistance | Resistor contacts |
0.38 ohm | 3 and 4 |
0.69 ohm | 3 and 2 |
1.69 ohm | 1 and 2 |
2.76 ohm | 1 and 4 |
Checking the blower speed switch (Ford)
Switch position (speed) | The circuit between the contacts is closed |
Low | – |
Second | 2 and 3 |
Third | 2 and 3, 2 and 4, 3 and 4 |
high | 2 and 4, 2 and 1, 4 and 1 |
Checking the blower speed switch (Mazda)
Switch position | Contact |
Any | F |
First position | E |
Second position | C |
Third position | A or D |
Fourth position | B or D |
On Mazda models, the fan relay is located in the right front corner of the engine compartment. Ford Probe models use two relays - 1993 models have a low speed relay mounted in front of the radiator, and later models in the left rear corner of the engine compartment. The fan high speed relay is located in the fan shroud itself.
The blower fan is located under the glove box.
Examination
1. If the blower fan is not working, first of all, check the connections of the connectors in the fan circuit. Check engine fuse (15 A) in the internal fuse panel and heater fuse (40 A) in the fuse and relay panel located under the hood.
2. Determine the location of the fan relay. Remove relays and check if they function properly (see subsection 12.5). Replace relay if necessary.
3. Check how the fan works in all modes.
4. If the fuses and relays are OK and the fan is not working, test the fan itself.
5. Connect tester to blue/red (Mazda) or white (Ford) contact. The tester must show at least 10 V (the ignition is on, the fan mode switch is in any position except the OFF position (Turned off). If not, there is a problem with the fan circuit.
6. If voltage is applied to the fan and it does not work, connect with a blue/white jumper (Mazda) or black/orange (Ford) wire to ground on the car body. If the fan still does not work, then it needs to be replaced. If the fan is running, it means there is a problem with the fan's ground circuit.
7. If the fan works but not in all modes, check the fan resistor located on the fan shroud.
8. Remove the resistor and inspect it for damage. Check the resistor with an ohmmeter (see fig. Blower Motor Resistor Test). Replace resistor if necessary.
9. If the resistor is functioning properly, remove the heater control panel. On Probe models, disconnect the wires from the back of the fan speed switch and check the resistance of the switch (see fig. Checking the blower speed switch (Ford). On Mazda models, connect a voltmeter to the switch terminals and check if voltage is applied to the terminals (see fig. Checking the blower speed switch (Mazda). If the switch is defective, replace it.