Windshield wipers are going backwords help!

OK so the deal is when i turn on the windshield wipers they attempt to go up but they never do unless you put them up then they go down so what is the problem??? PLEASE HELP

I smell an electrical problem unless you recently changed the wiper arms?

Hey thanks turns out they recently did, and forgot to tell me but the problem was they didnt tighten the bolt down, therefore i did and it fixed the problem. Thanks for the help.