Checking the tachometer on a car
- A) Connect the tuning control tachometer and start the engine.
Note: Reverse polarity when connecting a tachometer will damage the transistors and diodes.
- b) Compare the readings of the control and standard tachometers.
Tachometer readings (rpm) | Valid Range (rpm) |
700 | 610-750 |
1000 | 900-1100 |
2000 | 1875-2125 |
3000 | 2850-3150 |
4000 | 3850-4150 |
5000 | 4850-5150 |
6500 | 5820-6180 |
7000 | 6790-7120 |
If the error level is exceeded, replace the tachometer.
Checking the speed sensor
Measure resistance between leads "1" And "2". Resistance 730 Ohm.
If the resistance is out of specification, replace the sensor.