Installation 00-02-0268 page 1 of 2
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Designed for Use with Electric Swichgage instruments 
or Normally Open, Close to Negative Contacts
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LED Annunciation for Low Oil Pressure, 
High Water Temperature, Loss of Battery Voltage, 
and Low Fuel Level or Glow Plug.
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Output may be used for Tripping an Electromagnetic 
Control Switch for Engine Shutdown
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Developed with the Same Leading Edge Technology 
as Our EGS Series Electric Swichgage
Description
Murphy’s EN204 Tattletale Annunciator 
works with other engine components to 
clearly indicate critical engine operating 
conditions. The four bright LEDs on the 
face of the Annunciator indicate the cause 
of an alarm or shutdown condition.
Two EN204 models are available. Each 
shows the standard critical engine operating 
parameters—oil pressure, coolant temperature, and battery voltage. Model EN204-S12 also includes an indicator for low fuel 
level. Model EN204-SG-12 substitutes the 
fuel level indicator with a glow plug indicator for those engines that use a glow plug 
for easier starting.
The EN204 Annunciators are used in conjunction with Murphy Electric Swichgage 
instrument or other normally open switches 
that close to ground when a fault condition 
occurs. As an example, in a system with a 
Murphy EGS21P-100 Oil Pressure 
Swichgage instrument, the Swichgage closes to ground when the oil pressure drops 
below a pre-determined set point. This will 
energize the Oil Pressure LED on the 
EN204 to highlight a low oil pressure failure.
A very important feature of the EN204 is the 
ability to interface with Murphy 518PH or the 
760A Electromagnetic Switches to perform 
automatic engine shutdown when fault conditions occur. The EN204 can also be used with 
other Murphy visual and audible alarms 
(STAS series remote alarm, SAH audible 
alarm, and the TL7 visual alarm) for remote 
annunciation and equipment shutdown.
Basic Models
The following two basic models are offered:
The Switched functions listed above are able 
to sink a current up to 0.275 amps and may 
be used to activate the electromechanical 
control switches or other devices.
Specifications
Operating Voltage:
12 VDC (10 V min. - 16 V max.).
Current: 0.020 A to 0.025 A per LED. 
Output: Sink 0.275 A. 
Output Saturation Voltage:
.7-1.1 V @ 25°C.
Case and Screw-on Mounting Clamp:
Polyester (PBT).
Bezel: Bright stainless steel. 
Lens: Clear Polycarbonate, UV stabilized. 
Dial: Black background and white markings
with four (4) Red LED indicators. 
Wiring: Plug connector with wire leads, 
18 AWG (1.0 mm
2
) x 8 in. (203 mm) long.
Operating Temperature:
-40 to 185°F (-40 to +85°C). 
Storage Temperature:
-76 to 185°F (-60 to 85°C).
Shipping Weight: 0.5 lb. (226 g). 
Shipping Dimensions: 8 x 4 x 4-1/2 in. (203
x 102 x 114 mm).
How to Order
EN204-S-12  Four-LED Tattletale annunciator 
and switch including Fuel Level LED 
indicator.
EN204-SG-12 Four-LED Tattletale annunciator
including Glow Plug LED 
indicator.
EN204 Series
Monitored
Functions
Oil Pressure
Coolant
Temperature
Fuel Level
Battery
Voltage
Indicate and
Switched
Indicate and
Switched
Indicate and
Switched
Indicate 
Oil Pressure
Coolant
Temperature
Glow Plug
Energized
Battery
Voltage
Indicate and
Switched
Indicate and
Switched
Indicate
Indicate 
Action
Monitored
Functions
Action
EN204-S-12 EN204-SG-12
00-02-0268
Revised 03-06
Catalog Section 70
Four-Function 
Tattletale
® 
Annunciator