I just installed a radio on my 02 envoy slt and now the backlighting on my insturment cluster and a/c don't light. All other dimmable lights work ie window button lights information screen and a/c screen

Principles of Operation
Dimmable Backlighting The lighting control module (LCM) generates a variable pulse width modulated (PWM) voltage which is distributed to the dimmable components when the headlamp switch is in the parking lamps or headlamps ON positions. Light intensity is adjusted by rotating the instrument panel dimmer switch. The dimmable backlighting components consist of:

Your best bet might be to have a qualified repair shop check it .

All of these are not working ? Instrument Cluster and Panel Illumination The non-dimmable lighting system illuminates the following components:

• Roof opening panel control switch
• Window control switches
• Door lock control switches
• Sliding backlite window control switch

The dimmable panel lighting system illuminates the following components:

• Adjustable pedal switch
• Manual climate control assembly
• Electronic automatic temperature control (EATC) assembly
• Headlamp switch
• Instrument cluster
• Message center switch
• Audio unit
• Steering wheel audio and climate control switches
• Speed control switches
• Digital versatile disc (DVD) player
• Floor shifter
• Parking aid switch
• Four wheel drive (4WD) switch
• Traction control switch

The instrument panel dimmer switch is a contact switch that signals the desired level of brightness sent to the instrument cluster and dimmable components.
You checked all the fuse's ?

1. Visual Inspection Chart Mechanical Electrical
   • Headlamp switch
   • Central junction box (CJB) fuse(s):
     • 6 (15A)
     • 22 (10A)
   • CJB circuit breaker 401 (30A)
   • Auxiliary relay box 1 fuse 1 (5A)
   • Circuitry
   • Headlamp switch
   • Instrument panel dimmer switch
   • Clockspring
   • Illumination source(s)
   • CJB

Did you check these fuse's in the central junction box and

• Auxiliary relay box 1 fuse 1 (5A) You don't need to check them all ,just the right one's . How did you check them ? pull them out an look ?
• Principles of Operation
  Dimmable Illumination With the parking lamps ON, voltage is supplied to the instrument panel dimmer switch (part of the headlamp switch). The instrument panel dimmer switch then sends a variable pulse width modulated (PWM) voltage to the instrument cluster and other dimmable switches and components.
  Fixed Illumination With the ignition switch in the START or RUN position, the delay accessory relay provides voltage to the non-dimmable switches. The delay accessory relay is controlled through the instrument cluster.
  

Have you checked wiring harnesses that attach to cluster ?
Also check main ground wires that are part of the cluster.

Are these the lights you are talking about ?
Instrument Cluster and Panel Illumination The instrument cluster and panel illumination is used to provide backlighting to the instrument panel, switches, and control components when the headlamp switch is in either the PARKING LAMPS ON or HEADLAMPS ON position. The level of intensity is adjustable by rotating the instrument panel dimmer switch either up to increase intensity or down to decrease intensity.
Fixed Backlighting When the accessory delay relay is energized, switched voltage is supplied to the non-dimmable components and switches.
Dimmable Backlighting When the parking lamps or the headlamps are in the ON position the smart junction box (SJB) monitors the input from the instrument panel dimmer switch. The SJB sends a pulse-width modulated (PWM) voltage to the dimmable components and switches based on input received from the instrument panel dimmer switch. The SJB also sends a message over the controller area network (CAN) to the audio unit, and the instrument cluster to indicate the backlighting intensity level.
If you don't know about PWM an smart junction box your better off taking your vehicle to a quailified repair shop ! You don't the diagnostic tools or technical information . May have DTC'S - diagnostic trouble codes stored in the SJB (computer ). Do you know where SJB is located ?
Visual Inspection Chart Electrical

• Smart junction box (SJB) fuse 23 (15A)
• Bulb(s)
• Circuitry
• Connectors
• Illumination source(s)
• Auxiliary climate control switches (if equipped)
• Door lock control switches
• Window control switches
• Headlamp switch
• Dual electronic automatic temperature control (DEATC) module
• Audio unit
• SJB
• Instrument cluster

1. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

1. If the cause is not visually evident, connect the diagnostic tool to the data link connector (DLC) and select the vehicle to be tested from the diagnostic tool menu. If the diagnostic tool does not communicate with the vehicle:

• check that the program card is correctly installed.
• check the connections to the vehicle.
• check the ignition switch position.

1. If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool operating manual.

1. Carry out the diagnostic tool data link test. If the diagnostic tool responds with:

• CAN circuits fault; all electronic control units no response/not equipped, refer to Section 418-00 .
• No response/not equipped for SJB, refer to Section 419-10 .
• System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs, and carry out the self-test diagnostics for the SJB.

1. If the DTCs retrieved are related to the concern, go to the Smart Junction Box (SJB) Diagnostic Trouble Code (DTC) Index.

1. If no DTCs related to the concern are retrieved, GO to Symptom Chart .
2. • The control illumination is inoperative
   • Fuse
   • Smart junction box (SJB)
   • Go To Pinpoint Test A .
   • The instrument cluster illumination is inoperative
   • Instrument cluster
   • CHECK the audio unit illumination for correct operation.
     • If the audio unit illumination operates correctly, INSTALL a new instrument cluster. REFER to Section 413-01 . TEST the system for normal operation.
     • If the audio unit illumination does not operate correctly, REFER to Section 418-00 to continue diagnosis of the communications network.
   • The audio unit illumination is inoperative
   • Audio unit
   • CHECK the instrument cluster illumination for correct operation.
     • If the instrument cluster illumination operates correctly, REMOVE the audio unit. REFER to Section 415-01 . SEND it to an authorized repair facility. TEST the system for normal operation after the repair.
     • If the instrument cluster illumination does not operate correctly, REFER to Section 418-00 to continue diagnosis of the communications network.

you have to check the fuses to fix the instrument lights and check the switch in the top of the pedal brake for fix the tail lights.

did they all go out at once?
is the radio and climate control illuminated?

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Well, the problem is that I dont know the reason, you should investigate. There could be issues with lamps (must get new) or electricity problems (must head to auto-service)

If you have it all apart, I would replace all of them so you don't have to take it all apart again! Bulbs fail close to each other.

But not the error warning signal lights.

Generally the dashboard lights for the instrument cluster are directly above and below the cluster.

it sounds like you need a regulator for your alternater it is reversing polarity there for draining your battery and reseting the clock. it is located on the back of your alternator.hope this could help.