A little on my background, I have 23 years as an electronic technician in the Navy, and I still work the the electronics field working with SCADA communications for the Colorado River Municipal Water District (CRMWD).
What hampered me the most while working on this modification was limited wiring diagrams, not a knowledge or skill level.
I posted this thread to help others, just in case they try do this or something similar.
I searched VTXOA and VTXcafe and didn't find any thread like this.
As I said in my thread: I posted a Help post, and got some help from you all. "again thank you"
I think maybe electronics in general scares some folks a bit, by some of the comments listed.
I don't want to alienate anyone, and I have learned a great deal from these forums.
Back to the Temp light:
I tried several different configurations.
I hooked up to the Green/ Yellow wire the the Black LED (everything I found points to the Green/ Yellow being ground lead from the fuel tank), I put 12V positive on the Red LED.
When turning on the power to the bike the added Temp LED lit up (it should have been out like the one on the speedometer).
Next I tried swapping the inputs to the LED, moving the Black LED lead to the 12V and the Red LED lead to the Green/ Yellow temperature wire.
And believe it or not the added LED lit up again, very puzzling.
An LED is a diode after all and blocks DC in one direction.
Feeling beaten by only one LED reading, I moved forward with all the new information that I had found and posted this tread for all, to use if they wanted to.
David Hilton Ret. ETC/SS