FW Murphy, 78700003, MDDM Series Display and Diagnostic Module, Metri-Pack Connector, Bezel A-20 Type
This is a powerful, easy to use multifunction tool that enables the operator to view many different engine parameters and engine service codes.
It includes a two line by eight character backlit LCD display. The top line displays data labels, i.e. "EngHrs". The bottom line displays appropriate units information i.e "80 psi" for oil pressure.
The UP and DOWN push buttons located on the front, are used for scrolling through the parameters and viewing the menu list. Two LEDs (amber and red) are used to annunciate active fault messages received by the module.
Other components in the system are microprocessor-based analog gauges for displaying critical engine data broadcast by the ECM: engine RPM, oil pressure, coolant temperature, system voltage, etc., a combination audible alarm and relay unit for warning and shutdownannunciation.
For more information, please see 
Data Sheet
