And the resistor.

A Big thankyou goes out to WAYNE for Discovering this Interesting Quirk with the Fairmont Clusters, and for working out how to fix this problem !
NOTE : When fitting a Fairmont/Fairmont Ghia/EL-GT Instrument Cluster to a GLi/Futura/XR Model, you will need to add 1 Resistor to the Instrument Cluster, in order for the LCD Panels to Illuminate correctly.
Without this resistor, the LCD Panel(s) (Clock/Trip Computer/Climate Control/Odometer) will not Illuminate when the Park Lamps, or Headlamps have been switched on.
The reason for fitting this resistor is Fairmont/Fairmont Ghia/EL-GT/Fairlane/LTD Model Falcons use the Body Electronics Module to Dim the LCD Panels, when the Headlamps are switched On.
The Low and Mid Series Body Electronics Modules DO NOT HAVE THIS FACILITY.
Fords Method of getting around this problem, was to fit a Resistor the Instrument Clusters for use in GLi/Futura/XR Models.
This Resistor Feeds the Negative LCD Dimming Circuit, when the Park Lamps are on, and without it, the LCD Illumination Bulbs will not Illuminate.

Please Note : Fitting this resistor does not apply when fitting an XR Cluster, to a GLi/Futura/XR Model Falcon.

Finally, it is also worth noting that if fitting a GLi/Futura/XR clusters to a Fairmont/Fairmont Ghia/EL-GT, THIS RESISTOR WILL NEED TO BE REMOVED, and IN ORDER FOR THE Variable Dimming Function to work correctly with the LCD Panels.

The location of this resistor is on the Instrument Circuit Board, and is located to the right of the RHS Instrument Cluster Connector.
I.E. You will need to remove the Dials, and the circuit Board, flip the circuit board over, and solder the resistor in the position shown below.
The Following Picture will give you a better idea of its location,


The Resistor you will require is a 1Watt, 47 Ohm Resistor.
The Colour Bands for this resistor are Yellow, Violet, Black, Gold (5% Tolerance, 4 Band type).
Or for a 5 Band 1% Tolerance type resistor , the colour bands would be Yellow, Violet, Black, Black, Brown.
Please note though, you will Require a 1Watt type Resistor, due to the currents required by the LCD Panels.
The following are Catalogue Numbers for the above resistors, from various Electronics stores.
Jaycar - Cat RR-2542 - 47R 1 Watt Carbon Film, 5% ($0.32 Pkt of 2)
d**k Smith - R-1662 - Resistor 1W CF 47 Ohm, $0.10ea

Adding the Resistor
To do this, you will obviously need to remove the Instrument Cluster, and Disassemble.

To Disassemble the Instrument Cluster,

1.Remove the Clear Lens, and Black Plastic Lens Holder by removing the 2 Torx Screws Located at the top of the instrument cluster. (NOTE : You do not require a Torx bit to do this, a flat-headed screwdriver is perfectly adequate.)

2.Unclip the Black Plastic Lens Holder by unclipping the 2 clips at the top, and 3 clips at the bottom of the cluster.

3.Remove the Plastic Masking Lens away from the Dial Faces

4.Remove the 2 Torx Screws, Located at the back of the Instrument Cluster (Near the Bulb Holders). These screws are used to hold the Dial Faces in place.

5.Once these screws have been removed, gently ply the Dial faces away from their respective metal clips. This requires some force to do this, but it is important that you pull the faces directly up and away from the circuit board ! Do not try and Wiggle the faces away from the board.

6.To remove the Cluster Circuit Board, Remove the 2 Torx screws located At the bottom of the Circuit Board.

7.Finally, lift the circuit board from the top, up, and out of the Cluster casing. (Pulling the bottom electrical connectors out from the Casing housing).

Once the location is found, Heat up the Solder points outlined above, with a soldering iron, and attempt to clean the area of the solder.
Below the solder are mounting holes for the resistor. Removing the Excess Solder will allow the resistor to be mounted by placing its legs through these holes.
Once fitted, solder in place, and re-assemble the Instrument Cluster, and test.