Instrumentation Illumination Question

[Road Warrior H2]

I am not sure of the voltage, but would think 12V as I have not seen 5V lighting other then in electronic components.
If you can hook it up to the power plug and measure with a meter while you have it apart, that will tell you and also the polarity, because LED's will not work if installed reverse even in the plug in lighting available.
I was going to change some bulbs in my dash guages when I had the dash apart, but that is tape sealed with a sticker that says void if opened so I am not sure if those bulbs even can be changed or plug in and left it for now.
Maybe someone else has tried this and can let us all know..