Why aren't my instrument lights working and where is the dimmer switch

Maryellen Mcgee darn Jeep could not have made this more complicated. Most of the information I provided is not what you are looking for but may become important. the part about the dimmer switch is in bold

CLUSTER ILLUMINATION

The ElectroMechanical Instrument Cluster (EMIC) has several illumination lamps that are illuminated when the exterior lighting is turned on with the headlamp switch. The illumination intensity of these lamps is adjusted when the interior lighting control ring on the left control stalk of the multifunction switch is rotated (down to dim, up to brighten) to one of six available minor detent positions.

The Body Control Module (BCM) monitors a resistor multiplexed input from the multi-function switch on a panel lamps dimmer switch mux circuit. In response to that input, the BCM provides a control output to energize the park lamp relay and an electronic dimming level message to the EMIC over the Programmable Communications Interface (PCI) data bus based upon internal programming.

The EMIC receives the electronic dimming level message from the BCM, and a battery current input from the energized park lamp relay on the hard wired fused park lamp relay output. Based upon the dimming level message, the EMIC then converts the battery current input to the appropriate 12-volt Pulse Width Modulated (PWM) output. This PWM output is used to illuminate the cluster illumination lamps and the VFD on the EMIC circuit board, and provides a PWM output on the hard wired fused panel lamps dimmer switch signal circuit to control and synchronize the illumination intensity of other incandescent illumination lamps in the vehicle. The cluster illumination lamps are grounded at all times.

The BCM also sends electronic dimming level messages over the PCI data bus to other electronic modules in the vehicle to control and synchronize the illumination intensity of their VFD units to that of the EMIC VFD unit. In addition, the control ring on the left (lighting) control stalk of the multi-function switch has a Parade Mode position to provide a parade mode. The BCM monitors the request for this mode from the multi-function switch, then sends an electronic dimming level message to the over the PCI data bus to illuminate all VFD units in the vehicle at full (daytime) intensity for easier visibility when driving in daylight with the exterior lighting turned on.

The hard wired multi-function switch and EMIC panel lamps dimmer inputs and outputs may be diagnosed using conventional diagnostic methods. However, proper testing of the PWM output of the EMIC and the electronic dimming level messages sent by the BCM over the PCI data bus requires the use of a DRBIIIt scan tool. Refer to the appropriate diagnostic information.

You want to check fuse 9-13 and 34 in the fuse panel at the driver side on the end of the dashboard