Hey there.
A few months ago I turned the battery polarities wrong way, started up the engine and the cable from the alternator to the battery burned up. I changed the cable and noticed the tilt monitor and tachometer was dead.
Anyway. Now I have changed the tachometer to a new one, just like the old one I had (the new having lcd hourmeter while the old one had analogue) The new one is Sierra 65129P Lido. My engine is a Mercruiser 1.7 dti (boat from 2006) with alpha one gen 2.
I have connected the new one as the old and turned the settings to 2P 4C. I turned on power and the tachometer needle fell down to 0 rpm. I can see the light in the tachometer working and so does the hourmeter. Turning the engine on and it still shows 0 rpm.
What can be wrong here? I noticed on the wiring diagram that there is something called tach amplify circuit.
On the parts overview picture there is something called tach sensor (nr. 22). Nr. 21 is "tach module".
I measured voltage on the signal cable conencted to the gauge and it is showing about 13.3V.
As long there is power on the signal cable it is working? Or can tach sensor or something on the alternator be defective and it still will send 13.3V without rpm frequenzy?
A few months ago I turned the battery polarities wrong way, started up the engine and the cable from the alternator to the battery burned up. I changed the cable and noticed the tilt monitor and tachometer was dead.
Anyway. Now I have changed the tachometer to a new one, just like the old one I had (the new having lcd hourmeter while the old one had analogue) The new one is Sierra 65129P Lido. My engine is a Mercruiser 1.7 dti (boat from 2006) with alpha one gen 2.
I have connected the new one as the old and turned the settings to 2P 4C. I turned on power and the tachometer needle fell down to 0 rpm. I can see the light in the tachometer working and so does the hourmeter. Turning the engine on and it still shows 0 rpm.
What can be wrong here? I noticed on the wiring diagram that there is something called tach amplify circuit.
On the parts overview picture there is something called tach sensor (nr. 22). Nr. 21 is "tach module".
I measured voltage on the signal cable conencted to the gauge and it is showing about 13.3V.
As long there is power on the signal cable it is working? Or can tach sensor or something on the alternator be defective and it still will send 13.3V without rpm frequenzy?