Intermitant Cutting out

Hi Guys, ok i checked my pick up coils, number 1 and 4 is not getting any reading but 2 and 3 is.

My question, why would a pick up coil fail, and is there any way to solve this...what is this hair dryer thing about....can you just buy a set of pick up coils with out the plates etc....any idea of how to solve this . in cape town south africa, and very hard to pick up parts ...kz1000j 81 model...thanks