Dryer heat control does not seem to work. It is either really hot or no heat at all. It is a Kenmore Soft Heat Natural Gas dryer, I think it was built in the late 80s. Where should I start to fix this bugger? Thank you.

Ok, I have used a multimeter to check the thermostat heater, the cycling thermostat and the temperature selector switch. All of them checked out OK or at least within a few percentage points of where they are supposed to be.

Any other ideas? Again, the problem is I am not able to select lower temperatures while drying. Plenty of heat and of course tumbling and airflow, but I can't diminish the temperature.

A solution would be greatly appreciated!

Thanks in advance.