Yes, but based on that schematic, you also have a 1amp 200v diode in series with the circuit after the fuse.
I'll have a play and see if that's just a simple thing that i've overlooked.
Thanks for the Schematic!

_________________
Ongoing Project: 1972 Datsun 510 S13 SR20Det. http://ozdat.com/forum/viewtopic.php?f=33&t=17898
New Daily: D22 Navara (The new workhorse)
Retired 12/2016: MY98 Subaru Impreza RX
Previous Car: Restored Green 1972 Datsun 510, Hot L18

Here's a couple of variations on the Alternator Charge LED theme.

The circuit on the left is the most reliable, with least chance of the LED ever blowing due to overvoltage or reverse voltages. The bridge rectifier can be any cheap 200v 2A one you find lying around, or cheapest you can buy. You may need to adjust the resistor values slightly, as I just reduced their values slightly to allow for voltage drop across the bridge (diodes). With this circuit it doesn't matter which connection goes to IGN+ or Alternator, since it's using a bridge rectifier.

The circuit on the right should be reliable in most cases and may well outlast your alternator, even though it's the cheaper nastier version. Note that it definitely matters which connection goes to IGN+ and alternator. Adjust the 560R series resistor to suit the LED or change brightness. A super-bright 10mm LED may need a lower value resistor, for example.

In the relevant circuits, R1 and R3 control the LED brightness, or should be adjusted to suit the required LED current (usually about 20mA). R2 and R4 need to be 5watt and simulates the current limit (or drain) of a standard dash light bulb so the alternator works correctly.


{edited spelling}

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'71 Datsun 1600, SR20DET red-top
Mostly OK, needs typical rust and panel work.

The issue has been resolved. Thanks very much guy's.
I had a complete Noob moment.
I had originally wired the sense light up the same as the diagrams displayed. But I had wired it back to front originally and it wasn't working. I then changed the wiring around so that it was on, but wouldn't turn off. Without going into a long story, I did not have the resistor parallel to the bulb. I added a 120R resistor (because I had that and a 47R one) and it turned the light off straight away. Checked the voltage across the terminals with the engine running. 0.00v.

Really should have just done that in the past, pays to double check yourself sometimes. So now after years of putting up with a slightly dim charge light. The light is off!

_________________
Ongoing Project: 1972 Datsun 510 S13 SR20Det. http://ozdat.com/forum/viewtopic.php?f=33&t=17898
New Daily: D22 Navara (The new workhorse)
Retired 12/2016: MY98 Subaru Impreza RX
Previous Car: Restored Green 1972 Datsun 510, Hot L18

Hi Ross,

I use this site for me LED / resistor calculations

http://led.linear1.org/led.wiz

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1600 Build: http://ozdat.com/forum/viewtopic.php?f=59&t=22694

Ooh that's a handy site!
I don't know what was happening for me when I wired it up originally. I must have had a bad day then never bothered to re-check my wires to see if I had stuffed something up. It makes complete sense to have run the resistor in parallel which is what i thought I did, but then I remembered that I actually removed the resistor when I realised I wired the light in back to front one time. I never thought that I had.
I used to build guitar effects and things like that. The circuity is basic and the volts of the LED are lower than incandescent bulb, so none of it was making much sense. Anyway, it makes complete sense to me now, and its now fixed!

_________________
Ongoing Project: 1972 Datsun 510 S13 SR20Det. http://ozdat.com/forum/viewtopic.php?f=33&t=17898
New Daily: D22 Navara (The new workhorse)
Retired 12/2016: MY98 Subaru Impreza RX
Previous Car: Restored Green 1972 Datsun 510, Hot L18

Hey Ross,

It's a great site, takes a lot of the guesswork out of it

Good luck with it.

Cheers,

Trent

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1600 Build: http://ozdat.com/forum/viewtopic.php?f=59&t=22694