Several weeks ago my dryer stopped working and the E66 error code was displayed. I checked to make sure my vent was clean and open and found very little lint as we moved in the house only about 6 months ago. I replaced the Outlet Thermal Limiter and was back in business. It was about 3 weeks later, it happened again, E66. When it failed this time I wondered if it had to do anything with a lightning strike that hit our landscape lighting. It was sometime near the first Thermal Limiter failure but I'm not sure which came first. Had they occurred close in time, I think I would have expected that to be the problem. At any rate, the lightning event caused one of our hvac units to fail - which an hvac technician repaired with a new circuit board on the outside unit. So again, I inspected for blockages and also installed larger outside dryer exhaust vent. I replaced the Thermal Limiter again and I noticed the dryer seemed hotter than it should so I ran it on timed cycle and low heat as a precaution. It ran for a few weeks but has now failed again. I wish I had ran it on no heat to see if the elements were coming on went they shouldn't have - but I didn't think of that then. :( I checked the High Limit Thermostat and the Inlet Thermal Limiter with an ohmmeter at room temp and both indicated good - both showing continuity. I checked the elements and made sure they were okay and not being grounded by touching the duct. Also checked the Inlet Control Thermistor and the Outlet Control Thermistor and both were within specs at room temperature. So, then I opened up the encased motor/element control circuit board. I found the clear casing of the motor relay (RL2) had a burn mark at the contacts. The casings for the relays (RL5, RL6, RL7) that control the elements are not clear, they are black. I thought it might be possible that one or more of the three relays may be getting stuck. I checked with an ohmmeter and found the contacts open - which they should be. But, it (or they) may have only opened as I jostled the board trying to get all five tabs of the case that holds the motor/element control circuit board open. I'm not sure whether I should go ahead and replace both thermistors as a less expensive next step compared to replacing the motor/element control circuit board. Thoughts???