CS144 Alternator is not charging battery

[tamo3]

So, without key insert, voltmeter shows current voltage.

 

Once I turn key to ON position, Charge Warning lamp light up.

 

Is this expected behavior?

 

 

[TimZ]

53 minutes ago, tamo3 said:

Once I turn key to ON position, Charge Warning lamp light up.

Is this expected behavior?

 

 

Yes - the warning light should go off once you start the engine, and you should observe something like 13.8V (or whatever your regulator is set to) at the battery.

[tamo3]

Thanks Tim!

 

Here is the final result.

 

 

 

Is Voltmeter always showing current voltage, even though I did not insert key?

I'm afraid of drain battery..

 

 

[NewZed]

Not Tim, but...your video looks right, with the light coming on with the key (current passing from the battery through the charge/warning lamp to the alternator windings) and turning off when the engine starts (current generated by the alternator stopping flow from battery). 

 

But, you should rev the engine to 2000 - 2500 RPM too be sure that the regulator is limiting current.  Z's are notorious for having low output at idle RPM, and it's possible that over-voltage could happen with more RPM.  It should stick at 14.7, your idle voltage by your meter, as you rev the engine.  Up to 15 or so would be okay also.  16's, not so good.

 

Assuming that the regulator is regulating though, everything looks right.  Nice result after a lot of work. 

Edited January 2, 2018 by NewZed

[seattlejester]

Congrats on getting it running.

 

It shouldn't be reading all the time. There should be three wires, a power, a ground, and a read. From the characteristics it looks like you have the read and power wire switched. The read wire can have constant power as it only serves to differentiate from the charge to the ground. The power wire should be on the ignition so that it is off when you pull the key.

[tamo3]

Thanks NewZed! I will test it out tomorrow.

 

I found one more mistake.There were two IGN SW in previous schematic.

Here is updated version.

[tamo3]

Thanks seattlejester

 

I combine the IGN line to Charge warning lamp and Voltmeter.

Here is 77 280z schematic. '75 280z does not have IGN Relay.

[TimZ]

7 hours ago, seattlejester said:

Congrats on getting it running.

 

It shouldn't be reading all the time. There should be three wires, a power, a ground, and a read. From the characteristics it looks like you have the read and power wire switched. The read wire can have constant power as it only serves to differentiate from the charge to the ground. The power wire should be on the ignition so that it is off when you pull the key.

Actually Tamo3 has the voltage meter configured the way Datsun did it - hot at all times.  It certainly wouldn't hurt anything to rewire it as seattlejester suggests, but it doesn't draw very much current.

 

Tamo3 - great job!  Glad you stuck with it and got to the bottom of the issue.

[seattlejester]

Ah interesting. I was thinking from a multimeter perspective. I imagine the draw would indeed be minute given that multimeters usually run off tiny battery cells.