Home » Tony’s Tips » Articles » Electrical & Instrumentation » Understanding your SmartCraft 1.0 “Medusa” Vessel Adapter Harness

Understanding your SmartCraft 1.0 “Medusa” Vessel Adapter Harness

40 Pin Vessel Adapter Interface Connector – Mates to the SIM / ECM mounting plate 40 pin connector. All SmartCraft Input / Output signals pass through this connector. The installer must insure that the terminals on this connector are properly lubricated using Lubriplate ES-DS grease. Additionally, the installer is required to torque the jackscrew to 25 inch lbs. using a 4 mm hex wrench.

CAN BUSS Termination Connector – Engine end of buss loading resistors. Termination resistor cap (Part number 3969768) should be attached to this connector at all times in order to achieve proper resistive loading of the CAN buss. The termination resistor attached to the Vessel Adapter Harness at this point is not required to be removed for any vessel configuration. This Termination Resistor is REQUIRED in all SmartCraft Installations.

Paddle Wheel Input Connector – Hall Effect speed input to the SmartCraft system. The frequency of the input signal (Hz / cycles per second) can be modified using the Diesel View display to match the output frequency of the paddle wheel. Typical output frequency of these types of sensors are 4.9 Hz / mph or 5.7 Hz / knot. This input is OPTIONAL and only required if the system requires this signal input.

Tank 1 / Tank 2 Level Input Connectors – Variable resistive inputs to the SmartCraft system . The typical resistance range for these inputs is defined as 240 to 33 Ohms. The resistance reading for an empty tank will read 240 +/- 5 ohms while the resistance reading for a full tank will read 33+/- 5 ohms. The default transfer function is linear between these two points however it can be modified using the Diesel View to accommodate water / fuel tanks with irregular shapes. These inputs are OPTIONAL and only required if the system requires these signal inputs.

Rudder Angle Position Sensor Input Connector – Hall effect sensor input used to provide angular displacement of vessel rudder. Configuration / calibration of the rudder angle position sensor can be achieved using the DieselView display. The DieselView Display is required in order to display Vessel rudder angle. This input is OPTIONAL and only required if the system requires this signal input.

Throttle Signal Input – This signal input is REQUIRED for proper operation of the engine. This signal can be supplied by a throttle potentiometer which is supplied by a +5VDC reference from the ECM or by a valid voltage signal provided by an electronic throttle device.

Remote Throttle Signal Input / Bias Resistor – The Remote Throttle Bias Resistor is shipped attached to the Vessel Adapter Harness. This bias resistor is REQUIRED to be attached unless a Remote Throttle is installed in the vessel. If the bias resistor is removed and a Remote Throttle is not used a Remote Throttle fault will be activated by the ECM.

Helm Instruments Main Power Fuse – 10 Ampere fuse located in Vessel Adapter Harness. This fuse is designed and sized to protect against excessive current draw from helm mounted devices. All power required for engine crank and keyswitch power is supplied via this 10A fuse. This fuse is one of 4 in-line fuses supplied with the SmartCraft system. The other fuses and the purpose of each are described in earlier sections of this MAB.

Keyswitch Circuit Breakout Jumper – The keyswitch circuit is brought out at this point in order to accommodate engine compartment fire suppression systems. The fire suppression control module MUST provide a Normally Closed contact closure when the system is not activated. Upon activation of the fire suppression system this normally closed contact should open therefore disconnecting the keyswitch signal to the ECM resulting in the engine shutting down. The switch internal to the fire suppression controller shall be capable of switching 1A at a voltage range of 8 to 32 VDC.

24V to 12V DC/DC Converter Input – Cummins Mercruiser Diesel requires the use of a DC/DC converter when the engine(s) are being installed in a vessel that requires +24VDC vessel power. While the engine electrical system is capable of +24VDC operation, the SmartCraft system will only function properly at +12 VDC nominal voltage.

SmartCraft 1.0 “Medusa” harness fresh from the factory.
Here is the harness fresh from the factory.
Smartcraft Harness and Vessel View adapter
Smartcraft Harness and Vessel View adapter.
40 pin plug and 40 pin adapter
40 pin plug and 40 pin adapter.
SMARTCRAFT Vessel Adapter Harness. Ignition circut for QSB, QSC, QSL, QSM. Cut lead and engine will stop Used for shut down systems like the 'Fireboy'. Less than 1 amp
SMARTCRAFT Vessel Adapter Harness. Ignition circut for QSB, QSC, QSL, QSM. Cut lead and engine will stop. Used for shut down systems like the ‘Fireboy’. Less than 1 amp.