Proper Tools and Testing

^ Use a digital multi-meter with a minimum 10 mega-ohms internal impedance when testing the control unit or related components, unless use of an analog meter is specified by the testing procedure.

^ Analog meters have low internal impedance and cause circuit "loading" in low voltage circuits, resulting in inaccurate measurements and possible damage to components.

^ Do NOT use a self-powered test lamp to check for continuity.

^ Use of a multi-meter is necessary to obtain accurate measurements and avoid damaging low voltage control unit circuits and components.