Tachometer not working

[Stuey_15]

The tachometer is not working I have replaced the gauge and still not working the wiring seems fine what else can I check??

 

[wellcraft-classic210]

Re: Tachometer not working

Note; -- the informtion in this post is for an I/O -- not an outboard so it may not apply here. A good tach needs these things to work.

If you know how to use a DVM or can get help from someone who does that would be best to perform the checks below

--12v power supply ( check with volt meter to ensure 12 volts is present with POWER ON)
--Ground ( check with OHM meter to ensure ground is present with POWER OFF )
--Pulsing signal from coil --- verify wire is on coil in the correct location = distributor side of coil ( check wire continuity with OHM meter to engine with POWER OFF & wire removed from engine side)
--Setting on back for # of cylinders ( sometimes this switch connection gets corosion that can be fixed by moving the switch back and fourth a few times & then back to its proper setting).
--Good clean and tight electrical connections for all items listed above. ( Vibration can cause connections to be intermittent)
--Tachometer that is in woking order-- Verify on another vehicle if needed.

Good luck/ let us know what you find.

 

[Moody Blue]

Re: Tachometer not working

The tachometer is not working I have replaced the gauge and still not working the wiring seems fine what else can I check??

What setup are you talking about? Outboard or IO? What vintage? Was the tach ever working?

 

[Silvertip]

Re: Tachometer not working

Outboards do not derive the tach signal from the coil. It comes from the charging system and on most newer outboards is a 6 pulse setting on the back of the tach. Tachs on outboards do not care about the number of cylinders -- only the number of pulses from the charging system stator. Wiring "seems fine" is not a test. Measure it. Is your charging system working. A bad regulator will likely cause the tach to not function. Using a voltmeter, measure battery voltage with the engine running at 1500 - 2000 rpm (on muffs or in the water obviously). If it is 12.6 volts or less you have a charging system problem.

 

[ondarvr]

Re: Tachometer not working

Like St said, check the voltage while the motor is running above an idle, it should be moving higher than 13v or so as the RPM's increase. The tach gets it signal from the rectifier and a very common cause of a non working tach is a bad rectifier.