Just thought I'd share that the voltmeter actually works. i wanted to confirm that the battery was indeed dying, so I put the message display in Engineering Test mode and toggled through to the volt meter display. I then turned on both a/c blowers, head lights, and radio and watched the digital voltage quickly drop. Sure enough, the analog volt meter (battery guage) dropped too. Basically, anything below mid point (vertical) is getting below 12 volts. Battery was confirmed end of life.

The oil pressure guage is essentially and idot light, always in the middle position if the engine is running, and the pressure switch is made. The fuel level moves as it should (value between 0 & 255, which the Engineering Test mode will show).

I never see much movement on the temperature guage, even when towing, although my engine monitor will show temps rise from 200 to 220F sometimes.

 

Thanks for posting the voltmeter information.

How do you get to the engineering test mode?
I have a '07 Navigator.

Richard

 

For the Expedition, hold the reset button down while turning the ignition key to the run position. Hold it for about 10 seconds or so until the dash display says ENGINEERING TEST MODE. Toggle through the functions with a momentary push of the reset button. Go back one function with a slightly longer push of the reset button. Exit ENGINEERING TEST MODE by pushing the reset button a full second or so.


The test mode tests the gauges, all indicators, and will show the digital value for many parameters that are displayed on the instrument panel. It will stay in this mode after you start the vehicle. Shut off the engine or push the reset button longer to exit.


I found this for an explorer
How to Access Engineering Mode AKA Test Mode | Ford Explorer and Ranger Forums - Serious Explorations




GAUGE TEST - Runs the gauges from bottom to top.
Message Center Test - Illuminates all of the lights in the message center.
TELLTALE TEST - Illuminates all Warning/Advisory Lights
PART NUMBER - Not sure what part its for but it tells you a part number.
ROM CHECKSUM - ?
NVM LEVEL - ?
MANUFACTURE DATE - Self Explanatory
B&A CONFIG - ?
MANUF CONFIG - ?
CONTINUOUS DTC - ?
VEHICLE SPEED MPH - Digital Speedometer
VEHICLE SPEED KPH - Digital Speedometer
TACHOMETER - Digital Tachometer
FUEL LEVEL - ?
FUEL LEVEL % - ?
INSTANT DTE - Faster updating version of the DTE
FUEL ONOFF Z - ?
F#S ON/OFF Z - ?
COOLANT TEMP - Coolant Temp in Degrees C
ODOMETER
BATTERY - Battery Voltage
KEY IN SW - ?
DIMMING CMD - ?
DIMMING STEP - ?
MC SWITCH - ?
LWF OPS OAT - ?
COMPASS - Compass readout in degrees
LAST CHIME SOUNDED - Whatever the warning chime sounded for last