how to hook up a 4 wire tachometer

• 2023-08-08

The Tachometer has four wires. How to connect the four wires. 2. Black wire, the ground wire of the Tachometer, can be connected to any ground wire. 3. The yellow line is the working line of the Tachometer. After the yellow line is powered on, all parts of the Tachometer start to work, and the light on the panel lights up. The yellow line is connected to the power line behind the ignition key switch. After turning on the key switch, the Tachometer starts to work. 5. The green line is the signal line of the Tachometer and connected to the trigger signal terminal of the igniter. 

Find the positive and negative power poles of the on-board tachometer. Generally, the power line of the Tachometer is red and the ground line is black. Connect the power line and ground wire of the Tachometer to the positive and negative poles of the battery through a tool. Find the output signal line of the spark plug coil, usually a thick line and a thin line, which are the high voltage line and the low voltage line, and can be found through the vehicle's circuit diagram. Connect the signal wire of the Tachometer to the spark plug output signal wire, which is usually green or white.

The Tachometer can be used to judge the vehicle fault. For example, using a stall test to check the internal wear of an automatic transmission; The engine speed is very high but the vehicle speed is not high, and the fuel consumption increases significantly. It may be that the locking clutch of the Torque converter cannot be locked or the locking speed is too high; In situ acceleration test to check the engine working status, check whether the clutch of manual transmission models is slipping, and so on. These are commonly used fault detection methods by car repairmen. 

The speed in the red zone above the Tachometer is higher than that. For the engine, maintaining a longer rotational speed can lead to poor lubrication performance, and the burden of the heat dissipation system can cause damage to various components of the engine. Early cars set technology development on the Tachometer, and the protection mechanism of the engine is relatively sound. If the engine is in extreme conditions, the fuel will be cut off generally. However, some high-performance or low-end manual transmission models have a high tolerance for the engine's limit, and it is also necessary to judge the engine's condition based on the safety zone.