Check bulbs they are double filamented smaller for brake/ turn signals
Check the sockets for corrosion
Check for power and ground to sockets Could be a problem in the steering column switch
Possible causes include broken wire, failed switch, blown fuse, faulty flasher.
First check the flashers fuse .Then replace the flasher with a good one. There might be two-one for turn signals and one for 4ways. Or they could be one.
if only the turn signals are not working,you should replace the flasher can
Defective Flasher Relay.
Electric signals interpreted by your brain.
Your emergency lights are on.
bad temp sender usually. Bad gauge rarely.
There could be two causes for this. The first is the fuse is getting weak and the second is the relay isn't working.
It depends on the car. Some cars require that you turn on the turn signals to make the 4-way flasher work. If that's the case with your vehicle, make sure the emergency flashers aren't on. Otherwise, it's probably a problem with the turn signal switch.
Because the turn signals are a completely separate curcuit from the emergency 4 way lights. The turn signal wiring has a short that causes the fuse to blow out. In order to find that short, you need a technician that specialises in electrical wiring repairs, because you could spend days trying to find it and fail. It will cost some money but less than the value of the truck, or a traffic ticket for "no signals."
beleive there is a recall for that
there is a few things that could be wrong, its very possible that the timing chain is shot or the crank positioning sensor is bad