The correct connection method is:- The yellow wire of the meter does not need to be connected (if your sensor signal is 0~190ohm) - The black wire of the meter is connected to the negative pole of the power supply, - The red wire of the instrument is connected to the positive pole of the power supply, - Connect the blue wire of the meter to the brown wire of the sensor, - The blue wire of the sensor is connected to the negative pole of the power supplySensor Specification:- Protection ank: IP67 - Resolution range: 21 mm - Assembly: SAE standard 5 holes - Rated current for alarm switch: 500mA - Operating temperatures: - 40 to 85 Celsius - Fit for Fuel Level Gauge and Water Level Gauge - Sensor Length :150mm/200mm/250mm/300 mm ,350 mm , - Mounting: 5 pieces of M5 screws and 2 mm thick gasket - Output signal: 0~190 ohm (Standard European),Note:- Empty oil level : 0 ohm / 240 ohm - Full oil level : 190 ohm / 33 ohm - When the oil / water level is empty , there will be a space of 3-15mm between the sensor float and the bottom of the sensor. This is a safe distance, and the sensor can work normally,Thank you~ - When the oil / water level is full, there will be a space of 3-15mm between the sensor float and the top of the sensor. This is a safe distance, and the sensor can work normally, Thank you~Fuel Gauge Specification:- Material: PC Polycarbonate - Size: Approx. 8x8x7cm/3.15x3.15x2.76inch - Working voltage: 9-32V - Working current 60mm - Working temperature: -30~+75C - Gauge diameter: 52mm / 2inch -Warning Light : When Fuel level less than 13%, the warning light will flash .Package Include:1 X Fuel Level Sensor or 1 X 52mm Fuel Level Gauge