Attention! Gasoline is a flammable liquid, so when working with any element of the fuel system, take all fire safety measures. See the warning at the beginning of paragraph 2.
Examination
1. Disconnect the negative cable from the battery.
Warning. If your car's audio system is equipped with an anti-theft protection, make sure you know the unlock code before disconnecting the battery.
2. Remove the fuel pump from the fuel tank along with the fuel level sensor (see paragraph 5).
3. Using an ohmmeter, measure the resistance of the sensor at the connector. Measure the resistance with the float fully down (tank is empty) and fully raised float (tank full). The resistance should change smoothly.
4. When the tank is almost empty, the resistance of the sensor should be at its highest (approximately 105 ohm).
5. With a full tank, the sensor resistance should be very small - from 3 to 6 Ohm (Mazda) or 7 ohm (Ford).
6. If resistance differs from the specified values, replace the gauge.
Replacement
7. Disconnect the negative cable from the battery.
Warning. If your car's audio system is equipped with an anti-theft protection, make sure you know the unlock code before disconnecting the battery.
8. Remove the fuel pump from the fuel tank along with the fuel level sensor (see paragraph 5).
9. Disconnect the sensor connector from the base of the assembly (pic. 6.9).
10. Loosen the sensor mounting screws and remove it from the bracket (pic. 6.10).
11. Installation of the sensor is carried out in the reverse order. Install a new gasket under the flange.