Turn signal troubleshooting

[XcYZ]

A guy and his blonde girlfriend were driving to the movies one night for a date. As the guy was making a right turn, he noticed that his turn signal light inside the car didn't light up at all.

As he approached the next right turn, he asked his girlfriend to stick her head out the window to tell him if his turn signal was working. At the turn, she stuck her head out the window and replied, "It is...It isn't....It is.....It isn't....It is....It isn't."