Saintly Fish Posted November 15, 2021 Share Posted November 15, 2021 Or at least a lack of revs being displayed in the counter. Apart from a loose connection on the back of the dash unit, what else could cause this? And anybody got a clue where the needle gets the engine signal from?? Yanmar 6lpa dte Quote Link to comment Share on other sites More sharing options...
Geoff Posted November 15, 2021 Share Posted November 15, 2021 No coercion? - oh Neil you really are a lost cause. I believe the the rev counter signal usually comes from the generator (W?). Geoff. Maverick 1 Quote Link to comment Share on other sites More sharing options...
Andy135 Posted November 15, 2021 Share Posted November 15, 2021 Is the alternator still working/charging? Do you have a voltmeter on the dash and does it read 13-14v? If not, it may be that your alternator is failing. Quote Link to comment Share on other sites More sharing options...
Saintly Fish Posted November 15, 2021 Author Share Posted November 15, 2021 5 minutes ago, Andy135 said: Is the alternator still working/charging? Do you have a voltmeter on the dash and does it read 13-14v? If not, it may be that your alternator is failing. If you remember, when I had my new battery charger installed the alternator was removed and tested (couple of months ago). All was fine with it. Quote Link to comment Share on other sites More sharing options...
Saintly Fish Posted November 15, 2021 Author Share Posted November 15, 2021 23 minutes ago, Geoff said: No coercion? - oh Neil you really are a lost cause. I believe the the rev counter signal usually comes from the generator (W?). Geoff. Shove off. It's my phone/eye sight not me! Quote Link to comment Share on other sites More sharing options...
Andy135 Posted November 15, 2021 Share Posted November 15, 2021 12 minutes ago, Saintly Fish said: If you remember, when I had my new battery charger installed the alternator was removed and tested (couple of months ago). All was fine with it. I'd have thought it would be a loose connection somewhere then, either at the tacho end or at the alternator end. Any chance you could have knocked a connection loose when removing/reinstalling your water pump recently? Quote Link to comment Share on other sites More sharing options...
Saintly Fish Posted November 15, 2021 Author Share Posted November 15, 2021 14 minutes ago, Andy135 said: I'd have thought it would be a loose connection somewhere then, either at the tacho end or at the alternator end. Any chance you could have knocked a connection loose when removing/reinstalling your water pump recently? Possible I suppose, it's on the other side though. But I did also change the anodes and two are on the same side as the alternator. I will have a look later! I'm obvs not as slim as I thought. Quote Link to comment Share on other sites More sharing options...
suzook12 Posted November 15, 2021 Share Posted November 15, 2021 (edited) Check your connections, check the rev counter has a good earth and good power getting to it Edited November 15, 2021 by suzook12 Saintly Fish 1 Quote Link to comment Share on other sites More sharing options...
GPSguru Posted November 15, 2021 Share Posted November 15, 2021 5 hours ago, Saintly Fish said: Or at least a lack of revs being displayed in the counter. Apart from a loose connection on the back of the dash unit, what else could cause this? And anybody got a clue where the needle gets the engine signal from?? Yanmar 6lpa dte Normally, with an older tractor engines , the rev counter gets the signal from the 'W' terminal of the alternator. With newer engines, they get the signal from the crankshaft sensor, or some times the camshaft sensor and use the ecu to double the reading (camshaft turns at half engine speed). Saintly Fish 1 Quote Link to comment Share on other sites More sharing options...
Saintly Fish Posted November 16, 2021 Author Share Posted November 16, 2021 Apparently the tachometer sensor is here... On the flywheel housing. Port side of the engine. I will go and check all connections however. Quote Link to comment Share on other sites More sharing options...
captin slows old outlaw Posted November 16, 2021 Share Posted November 16, 2021 dont get stuck in there,or you will be there till you slim down 😂 a bit 😅 🤣 Saintly Fish 1 Quote Link to comment Share on other sites More sharing options...
Gordmac Posted November 16, 2021 Share Posted November 16, 2021 If it is an alternator signal check the belt isn't slipping a bit. Quote Link to comment Share on other sites More sharing options...
Andy135 Posted November 16, 2021 Share Posted November 16, 2021 4 hours ago, Saintly Fish said: Apparently the tachometer sensor is here... On the flywheel housing. Port side of the engine. I will go and check all connections however. If all the connections are sound, and if it's a hall effect sensor check the gap between the sensor and the flywheel teeth. The sensor bracket may have been nudged/bent out away from the teeth, which would give no signal. The gap between the two is usually surprisingly small when working properly. Quote Link to comment Share on other sites More sharing options...
Saintly Fish Posted November 16, 2021 Author Share Posted November 16, 2021 1 hour ago, Andy135 said: hall effect No idea what that is, I've not got the same googling time as you. Quote Link to comment Share on other sites More sharing options...
Andy135 Posted November 16, 2021 Share Posted November 16, 2021 5 minutes ago, Saintly Fish said: No idea what that is, I've not got the same googling time as you. No googling required. These are often used on cars to drive tachos, abs systems etc. I had to fight with one on a kit car I built years ago - never did get it to work properly in the end. https://en.wikipedia.org/wiki/Hall_effect_sensor Saintly Fish 1 Quote Link to comment Share on other sites More sharing options...
GPSguru Posted November 16, 2021 Share Posted November 16, 2021 6 hours ago, Saintly Fish said: Apparently the tachometer sensor is here... On the flywheel housing. Port side of the engine. I will go and check all connections however. Those hall effect (magnetic) sensors rarely fail. First port of call will be to check the wiring, especially the dashboard end. As a point of interest, the rev counter gauge itself could be at fault, I have known plenty to fail. Saintly Fish 1 Quote Link to comment Share on other sites More sharing options...
Odyssey Posted November 16, 2021 Share Posted November 16, 2021 Work back from the dash to the engine. If you can get a new Rev counter or a way to check the signal is there. It sounds like a bad connection so check it at the helm end and look for trapped wires in the middle. Hall effect sensors are very robust, far more so than optical ones so I would expect a broken wire somewhere Quote Link to comment Share on other sites More sharing options...
Popular Post Saintly Fish Posted November 16, 2021 Author Popular Post Share Posted November 16, 2021 Thanks all for your helpful suggestions. I have today fixed the issue. Turns out the spade connections on the sensor were a bit green, and one slightly loose. So a quick clean and squeeze resulted in..... Yey MegaByte, Geoff, JonC and 2 others 5 Quote Link to comment Share on other sites More sharing options...
Andy135 Posted November 16, 2021 Share Posted November 16, 2021 A quick and easy fix. Good result. 👍 Quote Link to comment Share on other sites More sharing options...
jonnyswamp Posted November 16, 2021 Share Posted November 16, 2021 Result 👍 I have the opposite problem, mine shows too high Quite common on arvors apparently Saintly Fish 1 Quote Link to comment Share on other sites More sharing options...
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