How to fix your vehicle’s tachometer

Thursday, August 10, 2017

While every driver focuses on the speedo and the fuel gauge, there’s another gauge to keep an eye on in your car: the tachometer. Otherwise known as the rev counter, it’s a useful tool for maintaining your gearbox and ensuring you aren’t overworking your engine at either end of the torque range. While they may not appear to be vital to the driving experience, it is a real issue, especially in a manual car, when the tachometer fails, leaving you relying entirely on engine noise to know when to change gear. When there are issues, there are a few things to check yourself and work you can do to fix the issue.

Blown fuses

Whenever you have an issue with your vehicle it is always worth checking the fuses as they are involved in almost every vehicle process and are relatively easy to replace yourself. Find the fuse box for your vehicle, as it is different for every car, and check the tachometer fuse for clouding or residue. If the fuse isn’t clear, replace it with a similar amperage fuse.

Bad wiring

Tachometer issues could also be linked to a wiring issue or a loose connection. Broken or corroded wires can cause the tachometer to be unresponsive or not work at all. To fix, refer to the owner’s manual and find the page dedicated to the Tachometer wiring. Once you have done this, you can check the relevant wires are in working order and make any changes where required. All wiring between the crankshaft generator, battery display, ECU, grounding wire and dashboard display should be checked for corrosion or loose connections.

LED display issues

This is usually the easiest to diagnose and fix. If the tachometer is not on the display, the underlying issue is typically a burned-out LED, especially if the light has had prolonged use. Once the LED is replaced, the rev counter should be up and running again as normal.  


It’s always worth keeping an eye on the tachometer and ensuring the reading corresponds with how the engine is functioning, including the engine sounds and vibrations compared to your speed. Unusually high or low readings for could hint at a problem with the rev counter. This can be easily sorted by resetting the meter, which will be outlined in the manufacturer’s manual.

However, there are some problems that you can’t fix. If you’re looking to buy or sell tachographs, why not come to the leading UK core broker? We have a great team of experienced professionals who work with auto components including non-digital tachometers, who can come out and visit you to evaluate your stock and provide you with a quote for any used parts overstock you have. If you want to find out more and to arrange a buyer visit, get in touch by calling 01789 722991 or you can email us.  


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