What is the reason for the engine tachometer not displaying?
2 Answers
The reason for the engine tachometer not displaying may include sensor failure or odometer damage. Disconnect the sensor connector, turn on the ignition switch, and locate the No. 2 electrode connected to the brown base with red stripe in the connector. Use a self-made wire with a plug to extend it and lightly scratch the grounding area of the vehicle body to input a pulse signal to the instrument. If the speedometer needle moves at this time, it indicates the instrument is normal, and the fault lies in the sensor reed switch tube or magnetic ring. In this case, it is recommended to contact a professional for repair. Connect a flexible shaft-type wire between the transmission and the odometer. During inspection, disconnect the transmission side and manually rotate it if it is not broken. The odometer should show movement. If the odometer does not move, it is recommended to check the odometer side and the odometer itself. If the wire is broken, it needs to be replaced.
When the tachometer doesn't light up, I think the most common issue is sensor-related, such as a faulty crankshaft position sensor. It's responsible for collecting engine speed signals, and if it's broken or covered in too much dust, the signal won't transmit. It could also be unstable circuit connections, like aging wires, loose connections, or short circuits, which directly interrupt data transmission. Or, the dashboard itself might be faulty, such as a broken screen or a blown fuse. I've experienced this myself while driving—after noticing the issue, I first checked the engine's operation to see if it sounded normal. If the engine was fine but the gauge wasn't moving, I had to manually inspect the fuse box. A non-working tachometer is quite dangerous, especially for manual transmission cars, as it can lead to inaccurate gear shifts and potential engine wear. I recommend getting it checked at a repair shop as soon as possible to avoid small problems turning into big ones. During regular maintenance, have a mechanic inspect the sensors and wiring to prevent such failures.
