Instrument panel lights are only fully on for left side of panel (gas gauge). Going from left to right they get dimmer to not on at all. Dimmer switch is fully functional. Fuses all ok.

Do the hazard light's work ? Did you try replacing the turn/ hazard flasher ?
Remove the LH instrument panel (IP) insulator. Refer to Instrument Panel Insulator Replacement in Instrument Panel, Gauges and Console.
Remove the steering column filler panel. Refer to Steering Column Opening Filler Replacement in Instrument Panel, Gauges and Console.
Grasp the hazard and turn signal flasher and slide the flasher to the right to release the flasher tabs from the slots on the BCM bracket.
Disconnect the electrical connector from the hazard and turn signal flasher.

Hazard Lamp/Turn Signal Lamp Flasher
Below left side of the IP, mounted on the multipurpose bracket, near the BCM

You must have bulb/bulbs popped, you need to take the clock panel out and replace the bulbs

Am I missing something or is everyone answering the wrong question?
If I am reading this right you are having problems in your instrument cluster in your dash not being lit up on one side, correct?
If so it is most likely a burnt out bulb or two.

The Panel Dimmer Control used to brighten the instrument panel also controls the dome lamp. Rotate the thumb wheel fully to the right, past the detent, dome light locks on. Try rotating it to the left.
It's next to your headlight switch. goodluck

The fuse panel is on the side of the dash where the drivers door opens up. The cover is right there. The diagram is on the back of the fuse panel cover. It will say cluster or dash Lts. If fuse is good try turning dimmer dial on left side of dash, it may be turned down just below gas guage

mcdevito75 here, It could be the dimmer section of the headlite switch, when dark outside put head lites on and see if you can turn the head lite switch either to the left or right to get the instrument panel lights on. Turning the headlites on and off could have turned the switch enough to keep the instrument lites from comming on, specially if your not the only driver.

A cluster is the "instrument cluster". The speedo, gas and temp gauges, tachometer etc. The cluster is serviced as a unit only. You cannot get individual components. You would be way better off sending your cluster to the remanufacturer to be rebuilt and sent back to you. Because if you buy a cluster from some place and give your cluster as a "core" and the one you bought is not the right one, you cannot return it for the right one. You will have to buy another one. They are NOT RETURNABLE. Good luck.

have you got a dimmer switch on your model to dim the dash lights. if you have it may be faulty. link the cables together if the lights work the switch is faulty. if you have not got a dimmer switch
your printed circuit on the back of the dash may be faulty or the plug in the back of the dash is not pushed all the way in. hope this helps

check the fuses ,could be a bad dimmer swicht or a blown light

The light behind myRemove the cluster bezel from the instrument panel. See Cluster Bezel in this group for the procedures.
Remove the four screws that secure the instrument cluster to the instrument panel Instrument Cluster Remove/Install
Pull the instrument cluster rearward to disengage the two self-docking wire harness connectors
NOTE: The instrument cluster has two self-docking wire harness connectors that will be automatically aligned with, and connected to the instrument panel wire harness when the cluster is installed in the instrument panel.
Remove the instrument cluster from the vehicle.
Reverse the removal procedures to install. Tighten the mounting screws to 2.2 N·m (20 in. lbs.)
when I turn my headlights on. All the other gauges are lit, but not the gas gauge. How do I get in there to replace the bulb and fix this? Or is it a fuse problem? I have a 1998 jeep scout Thanks