Coolant temperature gauge
If the pointer is constantly at the beginning of the scale, then with the ignition on, disconnect the wire from the pointer sensor and connect the tip of the wire to the housing. If the pointer deflects, then the sensor is faulty and must be replaced. If the pointer does not deflect, then remove the combination from the instrument panel, remove the red connector and, with the ignition on, connect the plug of the red connector of the instrument cluster to the housing. In this case, the deflection of the pointer will indicate the serviceability of the device and damage to the wire connecting the pointer sensor to the instrument cluster. If the pointer does not deflect, then replace the device or the entire instrument cluster.
If the pointer is constantly in the red zone, then with the ignition on, disconnect the wire from the sensor. If the sensor is faulty, the pointer should return to the beginning of the scale. If the pointer remains in the red zone, then either the wire has a short circuit with the housing, or the device is damaged. The serviceability of the device can be checked by disconnecting the red block from the instrument cluster. With the ignition on, the pointer should be at the beginning of the scale.
Fuel level indicator
The testing method is similar to that described above. If the pointer of the indicator is constantly at the beginning of the scale and does not deviate after the pink wire tip disconnected from the sensor is connected to the body, then the device must be checked. To do this, remove the instrument cluster, disconnect the red block of wires from it and, with the ignition on, connect the plug of the red block of the instrument cluster to the body. The pointer of a working device should deviate.
If the pointer is constantly at the end of the scale, the device can be checked by disconnecting the red wire block from the instrument cluster. In this case, the pointer of a working device with the ignition on should return to the beginning of the scale.
[The text is copied from the online portal: VazBook.ru]