Dryer Help

A week ago the dryer stopped heating. The wire from the high limit thermostat to the heater burnt into at the spade connector on the heater. The spade connector was very loose so I thought that caused the problem. I checked all of the thermostats and the thermistor with a multimeter while applying heat and they are working correctly. Checked the heater visually and with the meter and it is also good. Cleaned everything to be sure there is no lint build up any where. I installed a new wire with new spade connectors and made sure the connectors fit tight to the heater and put the unit back in service. It worked fine for a week and then burnt the wire into again. Any suggestions?