Try a led with a resistor. Tap the pos side to a8 (you will need a harness pin/wire) and the neg side to an alligator clip grounded to the body somewhere...
I did this and it comes on during startup (with the other gauge lights) but I haven't been into leanburn yet (new swap, still working out the bugs)
Let me know how this works! I think it will be what you are after
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