Tacho output from alternator

[Pedro_The_Swift]

I had a new 24v alternator installed in Port Hedland on the way up to Darwin, it now charges fine, but since then I have had no Tacho.( Original was cable driven)
2 different sparkies have tried and failed ( at great expense) to get it to work..

How should I test for "sense' output?

Oh,, and will that signal degenerate over 40' of 1mm cable?
(This tacho worked fine on the original alternator)

[p38arover]

From my reading on the 'net, the sense terminal won't be what you want. It is to sense battery voltage then adjust the alternator output.

You need the W (Waveform) terminal which is usually the tacho output. It's a connection to one of the stator windings. This might be the N winding on your alternator but alternatively the N terminal might connect to the centre point of a star connected stator, i.e., neutral.

It may be that you will have to open up the alternator and connect a wire to one of the stator windings to give you a W terminal

[p38arover]

(This tacho worked fine on the original alternator)

What are the terminals on the old alternator?

[Pedro_The_Swift]

Who knows... it was aparently toasted so in the bin would be my guess... might have been genuine Isuzu from '88....

[Pedro_The_Swift]

From my reading on the 'net, the sense terminal won't be what you want. It is to sense battery voltage then adjust the alternator output.

You need the W (Waveform) terminal which is usually the tacho output. It's a connection to one of the stator windings. This might be the N winding on your alternator but alternatively the N terminal might connect to the centre point of a star connected stator, i.e., neutral.

It may be that you will have to open up the alternator and connect a wire to one of the stator windings to give you a W terminal


This is what happened at Albany on the original alt...

I'd take the signal off an injection line but I doubt the bluetooth output would carry 40'.....