The tachometer is located on the dashboard next to the speedometer. It measures the revolutions per minutes (RPM). The tachometer can be a digital display or on a calibrated analogue dial. They are on both automatic and manual vehicles.

Purpose of the Tachometer

The tachometer shows the rotation of the engine’s crankshaft. The purpose of this is to help the driver in choosing the right throttle, and gear for driving conditions. For vehicles that have analogue dials, the danger area is marked in red. If the tachometer is driven in the red for too long, this can cause overheating, inadequate lubrication, and excessive wear on the engine. This can shorten the lifespan of the vehicle or cause the engine to fail.

Parts of the Tachometer

The dial of the tachometer has numbers ranging from one to seven on most vehicles. An indicator points to the numbers showing where your RPM is at while you are driving. There is a yellow area that means you are just starting to enter the danger zone. The red zone is normally around numbers six and seven and is the danger zone.

Potential Problems with a Tachometer

A blown fuse is a potential problem with the tachometer. Check the fuses to ensure they are properly functioning. Bad wiring can also be the cause of a malfunctioning tachometer. If you are getting erratic readings, this can be a sign of bad wiring. Another potential problem is calibration issues. If you notice the RPM readings do not coincide with the motor, then it may be time to have the mechanic look at the vehicle. By doing so, they can diagnose any problems that are going on. If you have a digital display, the LED lights may go out on the tachometer, or may not display correctly. Typically, a burned out LED is the cause of this. If you are still having issues with the tachometer after troubleshooting various problems, you may just have a bad tachometer. If this is the case, the tachometer needs to be replaced by a professional.

The purpose of the tachometer is to read the rotation of the engine’s crankshaft, which is shown in RPM. It is located next to the speedometer. If the dial goes into the red area, there may be a problem with your engine or the tachometer. If this is the case you can contact YourMechanic for an inspection.

This article originally appeared on YourMechanic.com as 3 Essential Things to Know About Your Car’s Tachometer and was authored by Valerie Johnston.


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