A tachometer is quite often used to measure the speed of rotation of objects, for example, to determine the speed of the crankshaft or generator. Almost all modern car models have a built-in tachometer. If there is no such device on the control panel or it is faulty, a separate tachometer can be connected to the generator.
It is necessary
- - tachometer;
- - tachometer operating manual;
- - insulated wire.
Instructions
Step 1
Learn how the tachometer works. Most electronic and electromechanical tachometers read the number of pulses that go to the coil (in gasoline engines) or from the corresponding terminal marked “W” (in diesel engines). At the same engine speed, the number of pulses coming from the generator output is approximately six times the number of pulses entering the coil. If you are unsure of the correct tachometer, consult your dealer if this type is suitable for your vehicle.
Step 2
Read the instructions for use of the tachometer to understand the installation sequence and the wiring diagram of the device. The principle of connecting the tachometer in most cases is as follows: the black wire goes to "ground", red - to "plus", green - to read the revolutions of the measured device.
Step 3
If the car is equipped with an electronic control unit, connect the green wire to the contact of the unit, from which the impulse goes to the standard tachometer. If the tachometer is not provided for by the design of the car, find the contact from which the output goes to the diagnostic block.
Step 4
For a diesel engine, there are special types of tachometers that are connected directly to the generator. Locate the terminal marked with the letter “W” on the generator and connect the input wire to it.
Step 5
If the specified terminal is missing from the vehicle generator, bring it out with a pre-insulated wire. Remove the generator and disassemble it. You will see three wires extending from the winding to the generator's built-in rectifier. Attach a wire to any of them and bring it outside. Reassemble the generator making sure the new wire does not touch any moving parts.
Step 6
Connect the rest of the wires from the tachometer to the generator, following the diagram (see figure).
