I've got a car adapter charger for use with a GPS unit which seems to be having a problem - and where it doesn't seem to be well . . . charging.
I've tested the cigarette lighter, to be sure that the circuit on that end is actually energized (it is), and I also checked the internal fuse in the adapter (it's intact). The adapter light doesn't illuminate (but it did previously), and clearly the GPS unit is not receiving power. The adapter doesn't really have any moving parts and isn't really very old and has seen only a limited amount of use - so I'm not sure where the problem is.
Candidly, I'm not even sure how to check the output from the adapter using my trusty voltmeter - since I'm not sure where/how you check the voltage output from the mini-USB plug, since there's not exactly any leads at the end of the plug (I know the output is supposed to be around 5v).
Early feedback will undoubtedly include some variation on, " . . . throw the adapter away, and buy another one for $5 . . .". Okay, got it - but I'd still be interested in troubleshooting the existing unit, if nothing else but for the experience obtained.