79' 318 ecu is live

If you look at the transistor you will note that there is an insulator between it and the box.

IIRC the metal housing of the box will have 0 volts when propperly grounded.

The housing of the transistor will have power.


The reason you have voltage everywhere when not grounded is the way transistors and other electronics work.

You are seeing power back feeding (sort of)

@67Dart273