What are the reasons for the car tachometer not working?

[Aurora]

Car tachometer not working reasons are: 1. Tachometer damage; 2. Tachometer needle stuck; 3. RPM sensor coil damage. Solutions for car tachometer not working: 1. Inspect and repair the car tachometer; 2. Clean dust and debris inside the tachometer; 3. Repair or replace the RPM sensor. The car tachometer is located in the instrument panel, symmetrically placed with the speedometer. Its working principle is: receiving pulse signals generated when the primary current in the ignition coil is interrupted, converting this signal into a displayable RPM value. The faster the engine speed, the more pulses the ignition coil generates, and the higher the RPM value displayed on the gauge.

[Riley]

As an enthusiast who often helps friends with car repairs, I've found there are quite a few reasons why a car's tachometer might stop working. The most common is a blown fuse in the instrument cluster - just check the fuse box under the hood or dashboard and replace it with a new one. It could also be a faulty speed sensor, that little component near the flywheel; poor contact or wiring shorts in the sensor can interrupt the signal. Another frequent issue is instrument cluster failure itself, especially in older cars where internal components may have deteriorated over time. Wiring problems like loose connections or corrosion can also prevent current from reaching the tachometer. Most importantly, this isn't something to delay fixing - driving without knowing your engine RPM could waste fuel or damage the engine. I strongly recommend visiting a repair shop promptly for professional diagnosis and repair, safety first.

[JoyRose]

I also experienced a malfunctioning tachometer while driving myself, and it was quite alarming at the time. I immediately checked the manual. The reasons can be summarized in a few points: either the fuse has blown, and you can replace it with a spare one from inside the car; or the sensor isn't receiving a signal, possibly due to dust or water causing a short circuit in the wiring; it could also be poor contact in the instrument control circuit, so try pushing the connector tighter; the worst-case scenario is an issue with the engine control module, where electrical signals aren't being transmitted, requiring professional equipment to diagnose. Remember to stay calm and use other gauges to estimate your speed while driving to avoid speeding. This issue is common, but timely handling will resolve it. Just in case, I always keep a spare fuse in my toolbox.

[LeAmir]

The tachometer not working? In most cases, it's caused by a blown fuse or sensor failure. Open the fuse box, refer to the manual to locate and replace the fuse; if there's no change, check if the tachometer sensor connection points are clean. Short circuits or overheating in the wiring may also interrupt the signal. Don't attempt to disassemble complex components yourself—safety first. Drive to an auto repair shop for diagnosis with a multimeter. Handle minor issues yourself, but leave major problems to the experts.