signals blinking

My turn signals are flashing on off really fast. Only the turn signals not the hazard lights those work fine. Does anyone know what the problem is?? In my dads truck the same thing was happening and all he did was replace this little box things which i think contolls the flashing.

Is it just flashing fast in the cab or outside to cause on some cars the dash lights flashing faster means you have a blown bulb

its a blown bulb its only blinking fast on one side ??

its blinking inside and out fast and on both sides. I have my rear lights unhooked could that be the prob. I should hook them up and check and check all my bulbs to see if theres one thats blown. Damn i should have done that before i posted. sorry

yeah man if your rear lights arent hooked up then that will be why they are blinking fast...without them plugged in i would think the truck thinks the bulb is blown

ya thats what it was