I bought a Tach off Ebay. It works fine and all but it has two extra wires that do nothing. I imagine one is the hot for the illumination and the other is the ground for same but they are both black. The bulb is blown out I think. It's brandname is "Monit" and it was $10.
If you can,open it up to change bulb,make sure the wires go to it.If not could be for a shift light? Probably for a bulb though.
I ran the two black wires just now. One I tied in to the ground for the foglight switch, the other I ran to the instrument fuse(which is blown and very tiny) The tach lit up like a magic charm. Now I guess I need to replace some bulbs in the dash because when I jumped the fuse, the climate control panel lit up strong and the upper portion of the speedo lit up weakly. Nothing on the left lit up at all. The High Beam bulb is bright and the left turn signal is bright with no right one at all. I hate removing gauges but I suppose now I can clean them and maybe reface them in white.
Cool. My gauges are still decent so the white face thing can wait. I do need a few bulbs replaced and the itty bitty fuse.