Instrument Features:1. Racing look enhances the character of your car/vehicle 2. Comes with installation manual. 3. Red backlight 4. High precision 5. Accessories: Tachometer suitable for cars/trucks/boats/diesel generator engines/gasoline enginesSpecifications:Material: stainless steel + nickel-plated plastic Working voltage: 12V/24V Indicating range: 3000/4000/60007000/8000RPM Adjustable speed ratio: 1-300 Protection level: IP67, can work at 1m underwater locationPackaging: 1PCS tachometer (adapter not included)Gasoline adapter:< br>1. Cable definition:Red: Power supply 12VDC Short black: Power supply GNDL Long black: Input signal wire Blue: Output signal (fixed 4 pulse/round RPM ratio) Brown: Switch control wire2. Configuration Steps:1. Connect the switch wire to enter setup mode 2. Find the ignition coil of the gasoline engine, usually it is near the spark plug, it can be easily found from the engine/car/vehicle user guide, wrap the uninput signal wire around the ignition coil cable 5-8 turns and tighten. 3. Turn on the sensor power, the LED will remain green. 4. Disconnect the switch cable, the LED will still remain green and count the pulses detected from the engine. 5. Connect the switch brown cable and disconnect again, the LED will flash. The 6 sensor outputs a pulse signal with a fixed speed RPM ratio of 4 pulses/revolution, which means it will output 66.6HZ at 1000RPM, for example, if the input frequency is 100hz 10000RPM, the sensor will convert the signal and then output 66.6hz 1000RPM. 7. How to configure the tachometer? Please set your tachometer RPM meter speed RPM ratio to 4 pulses/revolution and then the meter will work normally. Package: 1PCS Adapter (without tachometer)Diesel engine adapter:Cable definition:Red: Power supply 12V DC Black: Power supply GND Yellow: Output signal (fixed 4 pulses/rev speed ratio ) White: Switch Control CableConfiguration Steps:1) Connect the switch cable to enter setup mode 2) Find the original alternator of the vehicle, then install DR01 on top of the alternator as shown below, and install it securely: 3 ) Turn on the sensor power, the LED will remain green 4) Disconnect the switch cable, the LED will still remain green and count the pulses detected from the engine 5) Connect the switch brown cable and disconnect again, the LED will flash 6) The sensor outputs pulse signal, The fixed RPM rate is 4 pulses/revolution, which means it will output 66.6Hz at 1000RPM. For example, if the input frequency is 100Hz @1000RPM, the sensor will convert the signal and then output 66.6Hz @1000RPM7) How to configure the tachometer? Please set your tach/tachometer RPM ratio to 4 pulses/rev and the meter will work normally. Package: 1PCS adapter (not including tachometer)