Is there a way to test a dash bulb before I put it in the car? What about after it's in the car - does the bulb have to be plugged into the gauge (and grounded?) in order to see it light up?
What about the single and dual circuit bulbs for the turn signals/brake lights/etc. How can I test those without installing them?
I have a bunch of spares and would like to figure out which ones work.