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Aux output LED warning light "leaking" ground

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I added a Led warning light for water temp and oil pressure but looks like the ground is “leaking”. Even when the aux is off the led stay on (but not at full power/light).

To wire the Led, the positive is wired on a random 12v and the negative to the link, loom Ign7 and Ign8.

I tested the led before using the 12v wire and grounding it at the chassi and worked fine.

Am I doing something wrong?

WhatsApp Image 2019-07-12 at 12.01.22 AM(1).jpeg

WhatsApp Image 2019-07-12 at 12.01.22 AM.jpeg

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Subaru 99 Type RA.pclr

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The Ignition drives are only pulled up to about 6V when off so effectively you have 12V on one side of the LED and 6V on the other so some current will flow.  A couple of options you could try:

Try connecting the +ve side of the LED to the ign drive and the -ve side to ground, then reverse the activation logic.  The LED will then see 0V when "on" and 6V when "off", I think this will then work correctly.

Another option would be to leave the LED wired as it is now but add an extra pull up resistor to 12V (on the ecu side) so it has 12V on both sides when off. 

The 3rd option would be to swap the ignition drive with one of the proper aux outputs which have 12V pull-ups.  For instance you could move the fuel pump wire from aux 1 to ign 7 then use aux 1 for the LED.

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On 7/12/2019 at 12:58 AM, Adamw said:

The Ignition drives are only pulled up to about 6V when off so effectively you have 12V on one side of the LED and 6V on the other so some current will flow.  A couple of options you could try:

Try connecting the +ve side of the LED to the ign drive and the -ve side to ground, then reverse the activation logic.  The LED will then see 0V when "on" and 6V when "off", I think this will then work correctly.

Another option would be to leave the LED wired as it is now but add an extra pull up resistor to 12V (on the ecu side) so it has 12V on both sides when off. 

The 3rd option would be to swap the ignition drive with one of the proper aux outputs which have 12V pull-ups.  For instance you could move the fuel pump wire from aux 1 to ign 7 then use aux 1 for the LED.

Thanks @Adamw for the clarification.

The option 1 worked, but it was not bright as I was expecting.

So, I guess the option 2 will be more suitable since I don't wanna re-wire anything else.

Could you please guide me about the pull up resistor? I just need to add a resistor on the ECU side to transform the 6 to 12v right?
What would be the best value for the resistor? (tried to find it here but no success) 

Thanks!

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