CHF 768.45
CHF 768.45
excl. VAT
Not Available
This combination does not exist.
Units of Measure: Units
Add to basket
Product information:
Engine speed (tachometer) measured value is irregular, incorrect or not displayed.
The TN85A and the TN95A Economy and Standard tractors are equipped with an instrument panel (part number 47137566) with analogue measuring devices. However, the signal that the instrument panel receives from the alternator is an electronic signal in Hertz frequency (Hz).
The engine speed signal is received by pin W+ of the alternator and transmitted via the red (R) wire to pin 7 of the engine wiring harness (connection C1). The engine wiring harness is connected to the main wiring harness and the red (R) wire carries the signal to terminal B, pin 4. of the instrument panel.
Each engine revolution is equal to 18.87 pulses sent as one frequency. When troubleshooting problems related to the speedometer, check the alternator W+ connection for correct frequency: repair or replace the alternator if necessary
Motor speed Hertz (Hz)
500 rpm 154.1 to 160.4 Hz
1000 rpm 308.2 to 320.8 Hz
2000 rpm 616.4 to 641.6 Hz
Check the red (R) wire connected to the W+ terminal of the alternator to be sure the wire is not damaged or loose in the engine harness and the main harness to the instrument panel. Also make sure the instrument panel has a good, clean ground on top of the steering column bracket. Excess paint or corrosion will result in poor performance or erratic operation from the instrument panel.
If necessary, also access the rear cover of the speedometer / hour meter to check for dirt or damage and remove any dust.
Checkout
