Iam dealing with a sears kenmore dryer model#110.60932990 that has a heating problem.I replaced the heating element,thermistor,thermal cut-off,thermostat and the thermal fuse! The heating element will come on but then goes off and will not come back on and off like it should on the lowest cycle or knit settings.Could this be a bad heater relay? That's the only thing left to replace that I can think of?

FYI... your dryer doesn't have a heater relay. The four items you listed only make the dryer able to create heat, and have nothing to do with the dryers ability to get rid of the heat created. If you have replaced those 4 components, then you don't have a heating problem, you have a breathing problem. Most likely, the dryer isn't breathing well enough to dissipate the heat that the heater creates. The system won't try to turn the heater back on if it sees that it hasn't cooled back down to the cut-in temperature. First, make sure the lint screen is clean. Second, disconnect the dryer from the exhaust system and make sure there is at least 2 feet of empty space behind the dryer. Turn the dryer on and see what happens. Let me know the result.