Why do they call it a trouble lamp?

Because its easy to maneuver to work on cars or machinery.

Because they always give trouble. Mine does, anyway. Actually, it's because they were made to use when you have trouble to fix, in a place that doesn't have its own lighting, and it will light up the trouble area. Good question, though. We use stuff without ever thinking of why it's called what it is. Like our Canadian Employment Insurance program, which is meant to provide assistance if you don't have employment. To me, the name sounds like insurance you buy in case of the threat of a job coming your way, like fire insurance is for in case a fire happens.

Because every time you need one, you are either dealing with a problem or fixing something that is broken.