i know it can be replaced with just bulb, wired to the correct wires.. thats what i did.. old sportster speedo with bulb type indicators.. so that indicates to me all the idiot lite feed wires are putting out 12 volts..
ive been thinking about drag bars and a mount like you mentioned myself... the only lite im concerned with is oil pressure, my thought was to wire the oil pressure wire to the low fuel lite.. i never use that lite anyway since my tank lift, it comes on way to early.. so this way i would have just the speedo and a lite for low oil pressure.. just my take..

 

There is no such thing as a "12v LED". An LED is a diode that transmits light when it is biased. Connecting 12v directly to an LED will blow it up. As Joe mentioned - a "12v LED" certainly includes a resistor that will drop voltage and properly bias the diode. The entire system is 12v, some of the lamps are high sided to 12v with the switch to ground, while others are tied to ground on the low side and are switched to 12v on the high side. Electrically - there are no issues - physically - it's another story altogether. Joe and several others have figured out how to integrate into existing dashes (or even in the headlight). This certainly requires some mechanical skill (drilling holes without f'ing up ... not really my strong suite).
Your idiot lamp issue on superglide is common. Change bars and then - what to do with the idiots? I could never find an adequate aftermarket solution, the stock SG dash is tight to the tank, not as much room as a LR dash, but it can be done.

 

OK, so if the idiot light source wires are putting out 12 volts then I can cut off the stock indicator light assembly (shown below), install low profile LED assemblies (specified to operate from 12V source) in my dash, and correctly wiring it up in a neat and professional manner. Not a problem.





Thank you very much for all your help!

 

Make sure you post up pics when done. I almost went that same route with mine before deciding on my bars.