So I'm digging around in one of the bags with the snow chains, and wrapped up in rags is this little box with spare fuses, bulbs, etc.!
How thoughtful.
I know where all the bulbs go, except this one. It's too big for any socket I can find, and the prongs on the bottom look like they want to go into one of the relay slots.
Is it a relay tester? If so, how do you use it? Just plug it in and turn on the appropriate function, see if it lights up? Is it that simple?
