I do not have a tachometer on my boat. Since I am planning to move my starting panel, now would be the best time to install. Can someone tell me how to wire a tach to a diesel ?
How do I install a tach
- Thread starter tcbilgerat
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The common method to connect a tach is to the alternator. Tachs designed for diesels will connect to the alternator and are programmable in terms of pulses per engine rpm. The number of pulses per engine rpm will depend upon the number of poles in the alternator and the pulley ratio of the engine drive pulley to the alternator pulley.
I purchased a VDO programmable tach on eBay a couple years ago for $20 and installed it easily. Buttons on the back of the tach allow you to program the tach to display the correct speed.
You will need an optical tach to read the actual engine speed during calibration, but these are also available on eBay for under $30. See pix below.
I purchased a VDO programmable tach on eBay a couple years ago for $20 and installed it easily. Buttons on the back of the tach allow you to program the tach to display the correct speed.
You will need an optical tach to read the actual engine speed during calibration, but these are also available on eBay for under $30. See pix below.
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What diesel engine do you have? I have a Yanmar 3QM which seems common, but there were plenty of repowers or options otherwise.
My 3QM has a tachometer sensor/pickup on the flywheel, and I have a factory tachometer on the gauge cluster. Getting all the Yanmar stuff new is usually prohibitively expensive, so unless you get it used I agree that the alternator type is good enough and likely most affordable - that and you don't need to contort yourself to get to the back of the engine.
Just for some reference, this is a good site for photos of the rear main seal/flywheel/sensor. The connector is up by the piece of tape on the upper left corner of this image.
And here is the sensor.
My 3QM has a tachometer sensor/pickup on the flywheel, and I have a factory tachometer on the gauge cluster. Getting all the Yanmar stuff new is usually prohibitively expensive, so unless you get it used I agree that the alternator type is good enough and likely most affordable - that and you don't need to contort yourself to get to the back of the engine.
Just for some reference, this is a good site for photos of the rear main seal/flywheel/sensor. The connector is up by the piece of tape on the upper left corner of this image.
And here is the sensor.
Installed a tach sensor pickup at the transmission, there will be a plug installed at this location. I have a 2QM20, the hardest part was breaking the plug free. Lots of
pb blaster, 1/2" breaker bar and patience. Installed a teledyne tac, h2o temp,volt and oil pressure in place of the original warning lights.
pb blaster, 1/2" breaker bar and patience. Installed a teledyne tac, h2o temp,volt and oil pressure in place of the original warning lights.
Joe23455,
You said you installed a sensor pickup at the transmission. Was there a sensor already factory installed at the flywheel or did you have to do one? I have the same engine and am planning on doing the same thing with the engine panel. Any pictures you could post to give me an idea of the configuration would be greatly appreciated.
Thanks
Wally
You said you installed a sensor pickup at the transmission. Was there a sensor already factory installed at the flywheel or did you have to do one? I have the same engine and am planning on doing the same thing with the engine panel. Any pictures you could post to give me an idea of the configuration would be greatly appreciated.
ThanksWally
So yes I know this is for a 4JHE; principles and wiring is identical. See chapter 9, Section 9. This information applies generally to the QM engines as well as most of the other Yanmars I've seen.
http://sagaforumet.com/yanmar-manual/4JHE/kapittel_9.pdf
http://sagaforumet.com/yanmar-manual/4JHE/kapittel_9.pdf
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