Bought some JDM fogs from ebay last week on a whim, however i'm off on holiday in a few weeks & i'm totally skint so gonna stick them back on again (only to look for more in a month or two... i know, i know...)

Sooo - given that i'm useless mechanically/electrically - is there an easy way to test them to make sure they're fully functional before I re-sell them? They look in excellent condition but just want to be sure to keep myself straight...
Cheers!
John