Tachometer Wiring.

[fabricator-ken]

My Yanmar 4jh4 tachometer failed. Stopped showing revs and hours. So a electrician replaced it with a Kus tacho.
He could not get it to work. He said my alternator was not working. We had to leave, so had alternator checked at another town. It was working fine.
Still cannot get tacho working. It is showing the hours and revs of 100 regardless of throttle position.
Any ideas?

[daddle]

Is it possible that the original tachometer was engine-driven? An alternator-sensing tachometer will not work with the typical engine sensor. But the wire could be moved from the sensor to the alternator. Guessing...

[fabricator-ken]

I am told by Yanmar that the original tacho picks up the pulses from the W terminal on the alternator. I have that connected. I am wondering if this Kus tacho needs something different. I tried looking on the net can't find any info on them.

[fabricator-ken]

Does anyone know how to wire a Kus brand tachometer. I presume it takes its signal from the alternator on my 4JH4.

[DeepFrz]

You could always contact the mfg.
Dongguan Zhengyang Electronic Mechanical Ltd

Dongguan Zhengyang Electronic Mechanical Ltd (China Manufacturer) - Company Profile - DIYTrade China manufacturers suppliers directory

[fabricator-ken]

Thankyou. I have asked the question
Regards,
KEN

[Celestialsailor]

I had a 4JH and my pickup was back by the flywheel...not the alternator, as I recall.

[Atcman]

Did you ever manage to get your Kus tacho working?
I've just fitted one to a 2GM20 and I'm having trouble getting it to work. Any advice appreciated.
Thanks

[donradcliffe]

General advice--don't by something that has instructions in Chinese.

[jimbunyard]

Very generally, a diesel tach uses pulses generated from the alternator or a flywheel proximity sensor. If your tach sender wire comes from the alternator, the pulses the alternator generates must be matched to the tach, there's usually a selector switch on the tach. Not sure about how to match the output from a proximity sensor to the tach.


A gas engine tach generally reads the ignition circuit pulses of one cylinder to count rpms and won't work with a diesel engine.