So apply power to speedometer +12v, to 1K ohm R to PU, BK -12v, OIL LIGHT comes on, add -12v to BL light goes off, so apply 12+ to PU YL just to see is needle moves?
Should I leave the 1 K ohm R in to feed power to the speedometer PU, but go directly back to battery to do the quick test +12v...