Content

• Steps
• Part 1 of 2: Getting Started
• Part 2 of 2: Installing the tachometer
• Warnings
• What do you need

A car tachometer is a device that shows how many revolutions per minute the engine's crankshaft makes. In other words, a tachometer is a gauge for engine speed. Some cars are not equipped with tachometers; most often these are cars with automatic transmission. Most likely, the fact is that one of the main purposes of the tachometer is to facilitate the process of changing gears, to make it clear: the driver must see that it is time to change the gear. And even if your car is not equipped with a manual gearbox, it is still very useful to be able to observe the engine speed. Read on to find out the details.

Steps

Part 1 of 2: Getting Started

1. 1 Take out the tachometer and suitable terminals. You can buy and install both a new device (its price lies within the equivalent of $ 30-50), and an inexpensive used tachometer.
   • The only extra you need is a set of quick disconnect terminals. They can be purchased at any auto electrician store for the equivalent of $ 2-3. Keep in mind that the wire size is usually 0.5-1.0 mm², so select the correct size for the terminals.
2. 2 Adjust the tachometer to the number of cylinders of your engine. New tachometers are usually designed to work with four-, six- or eight-cylinder engines. For adjustment, you need to remove the cover from the back of the device, under which the switches for setting the number of cylinders are hidden.
   • Move the switches to the position corresponding to the number of cylinders of your engine. Remove and install the cover carefully so as not to damage the internal wiring of the tachometer. If necessary, use a screwdriver in the process.
   • Most often there are only two switches - # 1 and # 2. In most cases, the scheme is as follows: for a four-cylinder engine, both switches must be turned down, for an eight-cylinder engine, both up, and for a six-cylinder engine, # 2 must be moved down, and # 1 must be up. Be that as it may, if you have a new tachometer, then carefully read the instructions before setting up.
3. 3 Find the ignition distributor (distributor) output wire under the hood. Depending on the design of the motor, either alternating or direct current can flow through this wire; the same applies to other wires connected to the tachometer (ignition, lights, etc.). It is very important not to confuse anything and connect exactly the wires that are required to the device. Therefore, for a preliminary check, you may need a multimeter and a car repair manual with an electrical circuit.
   • It should be noted that some new tachometers are incompatible with high-voltage wires with an all-metal conductive core, so connecting the device without first reading the instructions can be dangerous.
4. 4 Check the connection. Before the final installation of the tachometer to the steering column, it would be a good idea to hook up all the wires, start the engine and make sure everything is working as it should. Do not drill the mounting holes without testing the correct connections. If there are no problems, then after connecting all the wires of the tachometer (including the mass), the device, after starting the engine, should give an accurate value of the engine speed and change the readings as the gas pedal is pressed.
   • Connect the tachometer to ground. Connect the ground wire coming out of the device to the car body. It is not necessary to pull the wire all the way to the negative terminal of the battery. Almost the entire body of the car is already connected to this terminal with a thick cable. Just route the tachometer ground wire to the point on the body where it will be more convenient to connect it.
   • Connect the appropriate tachometer wire to the ignition distributor output. The peculiarity of this wire is that it will have to be passed through the bulkhead of the engine compartment, since it must go directly to the engine. The location of the connection point for this wire may differ depending on the motor.

Part 2 of 2: Installing the tachometer

1. 1 Select a location for the tachometer. In most cases, the panel layout does not allow another instrument to be placed there, therefore, the tachometer is usually installed on the steering column.
   • Drill the mounting holes in the steering column and screw the mounting brackets (complete or self-made) to them. Installation instructions and necessary hardware are usually supplied with a new tachometer.
   • Attach the tachometer to the brackets on the steering column. If you do not have such staples, then make them or select the appropriate size and shape. They must firmly hold the device in the attachment points; for these purposes, ordinary U-shaped brackets are quite suitable. Screw them onto the steering column.
2. 2 Install the tachometer. Connect power to the device. To do this, connect the appropriate tachometer wire to the factory wiring assembly, from which 12 V goes to the panel backlight.
   • Also energize the tachometer scale backlight. Find the contact on the fuse box to which the wire comes from the headlight switch, and connect the tachometer backlight to it.
3. 3 Install the gasket into the hole in the bulkhead of the engine compartment. When you lead the wire from the tachometer to the engine, then when pulling it through the partition, it makes sense to install a rubber gasket in the hole. If the wire is rubbed against bare metal, it will eventually short-circuit and may even cause a fire. It is better to take care of safety in advance and install a gasket, especially since it will take a few minutes at most and will cost almost nothing.
4. 4 Adjust the gear shift lamp, if present. At certain engine speeds, this indicator will remind you that it is time to change gear. Not all tachometers are equipped with this feature. If your instance has it, then for further adjustment, refer to the instructions for your tachometer. It is not possible to adjust this indicator when the engine is running.

Warnings

• If you decide to install the tachometer on the steering column, then drill the mounting holes very carefully. Inadvertent drilling can damage the steering gear and / or internal steering column wiring.

What do you need

• Electric drill
• Screwdriver