In 1 LED Tachometer Digital RPM Voltmeter For Car Engine Speed Features:We can adopt 0.36 inch digital tube-shaped, suitable for 1 - 8 cylinder cars and 12V motor motors. Our products are made of shells and shine brighter. Display the battery voltage before and after engine startingWhen the car battery 12V overvoltage (overvoltage) or undervoltage, the alarm will flash. When the battery voltage is less than 11V (15V), the alarm will flash and display the actual battery voltage. Specification: Working Voltage: 8v - 17v Working Current: 40mA Voltage Accuracy: ± 0.1v and frac14; Rotational Accuracy: ± 30 rounds/min Maximum Rotation Rate: 100-31800round/min Bulb Color: Red Quantity: 1 Pc Other Devices: 1. This Auto Car RPM Meter 2 in 1 Meter Function Using Ultra Bright 0.36 Inch Digital Tube-Shaped Digital Display Instrument, Driven by High Performance MCU. It can be used in cars, motorcycle and other electronic ignition vehicles. Using high integrated design, size and appearance the same size as the single-function tachometer. It can be easily installed on the card in the support case.2. Behind the instrument, the button is used to adjust the internal parameters, when it is found that the speed display and the actual speed inconsistency, then we need to adjust the parameters (idle motorcycle 1100-1600, idle 750-1200, engine idle in just started at high level, the latest automobile stability decreased, such as changing the load of the air conditioning will affect the idle). Parameters according to the type of engine (such as horizontal crossbar, steel, four-cylinder), layout and position of wiring, in particular according to the parameters in more detail below as a reference. The parameter mismatch phenomenon is displayed, and the speed of the actual difference is an integer number of times or several times. This will reset the normal parameters on it. Before installation, please read the following details carefully, timely problems, and customer service. We are very happy with your response to the troubleshooting. How to adjust the rotation speed parameters, if the actual speed is different from the display speedLong press for more than 3 seconds to enter the setting state, short press select the frequency, long press more than 3 seconds to confirm, This is ok. The parameters are stored in the internal chip even if the power cut and parameters are not lost. The default parameters of this meter are 22.1 parameters: adjust to the frequency of 8.33Hz/1000 RPM per cylinder of ignition EFI of car use.2.2 parameter (default setting): suitable for the frequency of 16.66Hz/1000 of the four-cylinder EFI (second igniter) and two-stroke and four-stroke motorcycles.2.3 parameters: three cylinder cars for use at 25.00Hz/1000 RPM2.4 parameters: four cylinder cars are suitable for the frequency of 33.33Hz/1000 rpm of rail (with electric cars) fuse.2.5 Parameters: Eight cylinder cars are suitable for 66.67Hz/1000 rpm rail frequency.2.6 Parameters: Six cylinder cars are suitable for 50.00Hz/1000 rpm rail frequency.3. This meter automatically displays the car engine. When you start the car engine, it starts showing speed. If the battery voltage is greater than 15V(gt; 15V)The display speed of the meter will flash and flash, which is an alarm. And it will notify you that the car battery voltage is over. If the engine reaches a speed of more than 10000rpm, such as 15000r/min, the car tachometer will display-1504. Operating Voltage: DC 8V -17V Current: 40mA Voltage Accuracy: +/-0.1V; Speed accuracy: +/-30r/min5. How to connect: Black wire: ground wire, connect battery negative output (DC - )Red wire: power, connect battery positive output (DC+)Yellow wire: speed signal cable, connect to ignition outlet or trigger linesÂ~?~?6. Installation Guide: 6.1 connect the red and black wire in the advanced to make sure the display is normal for operation, then connect another wire. Note!6.2 speed signal from the engine ignition signal, can have multiple wire connections6.2.1. Electronic tachometer wire (some car models have a special wire for speed, if the connection, it will have the best signal quality)6.2.2 high voltage ignition coil inlet wire (if the car does not have a special speed line, we recommend connecting here)6.2.3 ignition output wire6.2.4 ignition trigger inlet line6.2.5 drain coil outletSince every car line is not always the same, first of all, the wiring position may vary degree of interference, as a result of which the speed signal is not stable,If your car model has a special electronic tachometer line, connect it, and the signal will be absolutely no problem, so the best choice is 6.2.1If there is no special electronic tachometer line, you should also connect the inlet wire of the high-voltage ignition coil. So the second choice is 6.2.2A note! Never connect the singal cable to the high voltage outlet wire of the high voltage ignition coil. You will burn this automati