HI I just purchased a 66 tbird and the 4ways dont work.is there any way to check the flasher? Ihave power going in but none coming.And is there 2 flasher on these car,s?All my turning signals work good HELP Thanks Ed

Yes there are two flashers just locate them and switch the two for a fast easy test, when you buy a new flasher always buy a 'heavy duty' one, it works with any number of bulbs in the circuit.
Usually the turn signal flasher is not a heavy duty one, but the 4way is always a heavy duty.
Price difference should be very minor. There are two prong and three prong flashers and can not be inter-used also substitute a flasher from ANY make of car they are all the same, 2 or (usually Mopar)3 prongs. The standard flasher will work at a different speed, depending on how many bulbs are connected, where the heavy duty one automatically adjusts it's speed. George