Blinkers wont blink(front or back)what causes.

Is it only one side that doesn't blink and the other side does?
If it's both sides, then the flasher is bad (located int he fuse box under the dash).

If only one side them check the ground at the front and rear light sockets. Often the socket will become rusted causing a bad ground. Clean the contacts where the screws hold the light socket onto the body to get good grounds.