Dryer does not heat and 3 of the 4 cycles do not time down?

How old is this drier? If it is over 2 years old it probably is dirty and the safety switch has shut down the heat strips. To cure the problem you have to disassemble the drier and clean out all dirt and lint deposits. This means taking out all duct work and washing the parts out including the blower fan. Vacuum out motor. Then replace blown safety which you have to find with ohm meter. DrTom4444