Geistware, I have a Bosch cap that has the ground soldered to the cap then it is secured with a clamp. The only thing that is different from the test stand setup is a contact switch between the positive battery lead ( from the on/off switch) to the ignition battery to open the circuit to kill the ignition. Could that have fried my sensor? I'm dead in the water now as CH Ignitions is closed until Sept. 20, due to family medical emergency. Hope everything turns out ok there. Is there any other place to purchase a new sensor for my engine? It's going to turn into winter before I can maiden my new plane.[]