This problem falls into the category of 'life's little gotcha'.  Bob installed his ECM into the Stag and got a bit of a surprise when the ECM turned on with the key off.  What was happening was one side of his radiator fan relay is tied directly to the battery and the other side to our relay driver U30.  The DS3658N drivers have internal protection diodes tied to the ECM's battery input.  Well the current flowed through the relay coil forward biasing these protection diodes which tried to turn on the ECM with the key off.  Sweet.....  A zener diode in series with the DS3658N internal diodes will prevent them from being turned on when the battery source is not applied to the ECM and also keep the peak voltage excursion below the 70 volts breakdown of the driver.