1. It is not the vent pipe. Cleaned it and have run it without the vent pipe for a while - still stops.
2. It is not the electronic dry sensor. It stops on the timed cycle too, as well as automatic cycle. I also removed the sensor circuit board and run just on timed cycle and problem persists.
3. Does not seem to be any motor amp or overheat thermal switches since the dryer immediately will restart right after it stops. Typically, they must have time to cool.
4. I can't find any problem with the door switch - but my next move is to take it out of the circuit.
What else could cause the dryer to stop? It is not just the heat kicking off, but the drum too.