mercury outboard tachometer troubleshooting

• 2023-07-11

The common problem with mercury outboard engine tachometers is that they do not work. The reason is that there is a malfunction in the circuit or instrument itself.

Follow the following steps to troubleshoot the engine tachometer:
(1) Check if the "No.1" terminal of the ignition coil has good contact.
(2) Check if the black three hole socket behind the tachometer is in good contact .
(3) Check the operation of the three hole socket with a multimeter. If socket A is poorly grounded, check if the brown wire in the white 14 hole socket of the instrument harness connector is grounded; If there is no voltage in socket B when the ignition switch is turned to "on", check if the black wire in the black 14 hole socket of the instrument harness connector has power voltage; When the ignition switch is turned to "on" , if there is no voltage at socket C , check whether the red/black wire in the white 14 hole socket of the instrument harness connector has good contact with terminal "1" of the ignition coil.If the black three hole socket harness behind the tachometer is checked to be all normal, the fault is in the tachometer itself and the tachometer should be replaced.

Perhaps there is a malfunction in the speedometer of the mercury outboard's instrument assembly, causing the pointer of this meter to not rotate; It is possible that the wheel speed sensor of the vehicle has malfunctioned, causing the meter to not rotate; It is possible that the mileage sensor of the mercury outboard has malfunctioned, causing the meter to stop working. Computer power cord failure can lead to poor performance and reduced economy of mercury outboard engines, so it is necessary to first check the computer power cord before replacing the mercury outboard computer. The power cord should include the ground wire to be considered a complete power cord. The tachometer has no or unstable indication . Check: There is no indication on the tachometer: First, check the tachometer sensor, unplug the sensor connector, and use a multimeter to measure the sensor resistance. The normal resistance value is 1050-11500. When the engine is idling , use a multimeter to measure the output voltage at both ends in the AC voltage range, which is normally greater than 0 8V . If the sensor is intact, check the tachometer circuit and tachometer.