Modulation lamp does not light when i talk - Galaxy Radios DX-95T Base CB Radio

If your talking about, lamp out warning, I don't think the drl has anything to do with it. Just my opinion.

The stop lamps on your vehicle are controlled (turned on by the BCM ) - body control module ,turn signal lamps as well . Your vehicle doesn't have a normal brake light switch ,has a low voltage sensor , not to say they can't go bad .
Turn Signal Lamps
The body control module (BCM) is responsible for controlling the turn signals and hazard lamps. When the turn signal switch is placed in either the left turn or right turn position, the BCM receives a signal from the turn signal switch. The BCM then sends an on-off voltage signal to either the left or right turn signals and their instrument panel cluster (IPC) indicator. When the hazard switch is pressed, the BCM receives a signal from the hazard switch. The BCM then will send an on-off voltage signal to all the turn signal lamps. All the turn signal lamps will flash including both IPC turn signal indicators.
Stop Lamps
The body control module (BCM) is responsible for controlling the stop lamps. When the driver presses the brake pedal, the BCM will receive a signal from the brake pedal position sensor. The BCM then supplies battery positive voltage to both left and right stop lamp assemblies and to the center high mounted stop lamp (CHMSL). The stop lamps are grounded at G401 and G403. The CHMSL is grounded at G302.

The first step in the diagnostic process should always be to check for DTC'S - diagnostic trouble code's ,an follow a service diagnostic trouble chart ,testing electrical circuit's .Not listen to someone say it's the brake switch , because in most case's he has no ideal what he's talking about . I have 30 year's GM experience , the level of electronic's on your vehicle , most people just don't have a clue . Your best bet ,take it to a qualified repair shop . That doesn't mean the dealer either . A lot of good independent repair shop's out there .

Your talking about the rear park lamps, but, do the front park lamps work?
Note the picture.
Underhood fuse box, 68 is park lamp relay, 69 is park lamp fuse.

Hi Rich , what lights are you talking about ? Exterior Lighting , Interior Lighting ? It doesn't matter All lights are controlled by SJB smart junction box ! An you can't just stick in a used one , It will need to be programmed ! Interior Lighting The interior lighting system consists of the following components:

• Smart junction box (SJB)
• Dimmer control switch
• Interior/map lamps
• Cargo lamp
• Glove compartment lamp
• Vanity mirror lamps
• Door ajar switches
• Puddle lamps

The interior lighting system consists of 2 subsystems:

• Courtesy lamps
• Demand lamps

The courtesy lamps are controlled by the SJB. The courtesy lamp subsystem consists of the interior dome lamps, the puddle lamps and the overhead console lamps (if equipped). The SJB supplies voltage to the courtesy lamps when the SJB receives the required input.
The demand lamps are controlled by the SJB. The demand lamps subsystem consists of the glove compartment lamp, all map/reading lamps, and the left and right vanity mirror lamps.
The SJB supplies power to the interior lighting system. The SJB will set DTCs if certain circuit failures exist with the interior lighting system.
Exterior Lighting Headlamps
The headlamp system is a dual-beam pattern system. It consists of a low and high beam, with a replaceable bulb. The headlamp assembly has the park/turn indicator lamp integrated into the headlamp assembly. The smart junction box (SJB) supplies voltage to the headlamps when demanded.
Principles of Operation
The SJB receives inputs and delivers outputs to a majority of the electronically-controlled features of the vehicle. The SJB constantly monitors the systems under its control and reports a concern in the form of a DTC. The DTC can be retrieved with a scan tool through the medium speed controller area network (CAN) communication network.
NOTE: Prior to the removal of the SJB, it is necessary to upload the module configuration information to the diagnostic tool. This information must be downloaded to the new SJB after installation. For additional information, refer to Section 418-01 .

In the instrument panel fuse box fuse # 8 CTSY LP 10A ,that's for the dome lights, fuse panel is left side of IP. What are you talking about 4 who drive won't light up or work ? 4 wheel drive ? Do you have two speed automatic or two speed selectable ?
Switch Indicator Lamps Do Not Light - One or More ? Check fuse #15 IP fuse box 10A 4WD . This is for two speed auto !

Circuit Description

The indicator lamps circuits consist of 5 individual lamps contained inside the mode/range switch assembly, they are AUTO, 4WD, 2HI, 4HI, 4LO and NEUTRAL. The AUTO, 4WD, 2HI, 4HI, and 4LO lamps are contained inside their respective range button. When the ignition is ON, the transfer case shift control module illuminates the indicator lamp that corresponds to the current ATC gear position by providing a ground through a current limiting driver.
The transfer case shift control module flashes each indicator lamp after a shift has been requested and will continue to flash until the transfer case shift control module can complete the shift. After a shift to AUTO, 4WD, 2HI, 4HI, or 4LO is made, the transfer case shift control module will flash that indicator lamp until the transfer case shift control module receives a high voltage signal on CKT 1695 from the front axle switch.
A solid state circuit located inside the switch supplies ignition voltage to the lamps. The solid state circuit also receives voltage whenever the headlamp switch is in park or headlamp position. When the solid state circuit receives voltage from the headlamp switch it will reduce the voltage that it supplies to the indicator lamps, dimming the lamps when the headlamps are ON.

are u talking bout rf meter or tx light

Codes that light check engine lamp are emissions/engine performance related only. Your DRL and SDM both talk to the ECM for inputs (they need to know if its running), but they dont affect the engine or tell the engine module to change how it runs.
Your ABS can affect how the engine runs as it sends wheel speed information that is used to adjust engine output, transmission shifting, and fuel/timing in some circumstances.
Check the ABS module for signs of water or oil affecting it, or water in the connector plug. Also check the harness where it leaves the module to make sure it isnt rubbing thru anywhere you can see.

GM ABS modules are not uncommon failure items, however mostly they set module fault codes or motor amperage/function codes. Id start with further diagnostics of the ABS.

NOTE: using generic OBD2 scan mode will show you only codes that are check engine lamp related if you want to be sure. Enhanced scan mode shows you any and all, and some of them simply have nothing to do with the engine lamp being on.

He is talking about the light switch itself. The lighting control module is just a big technical word for the light switch.

Circuit Protection Fuses/ Circuit Breakers Flashers are serviced as part of the lighting control module.
(Special police packages have flasher units and relays in the trunk relay center)
The Lighting Control Module (LCM) contains controls for both interior and exterior lighting, back lighting, the battery saver and various warning chimes.
The LCM eliminates the electronic interference and heat associated with the thermo-electric devices (bi-metallic and other mechanical flashers) used previously. The LCM is a microprocessor module that commands several lighting subsystems. It responds to electrical input signals from the vehicles various switches, sensors, and external modules.
LCM subsystem functions include:

• Headlamps with auto-lamps
• Turn signal lamps/hazard flasher lamps
• Cornering lamps
• Parking lamps
• Courtesy lamps
• Demand lamps
• Battery saver
• Backlighting

Interfacing with the Driver Door Module (DDM) via Standard Corporate Protocol (SCP) for illuminated entry

your owner manual sould have fuse chart. Some fuses/ekays in enine compartment. Some in car on left side of instrument panel

in car


Fuse Amps Circuits Protected 1 10 Power Mirrors, Anti-Theft Warning Light, Diagnostic Connector 2 5 Generic Electronic Module, Start Interrupt Relay Coil 3 5 Radio Illumination, Remote Radio Illumination, Electronic Instrument Cluster, Electronic Instrument Cluster PRNDL Illumination, Electronic Instrument Cluster Switch Module, Analog Cluster Illumination, Instrument Illumination 4 — Not Used 5 — Not Used 6 15 Rear Quarter Windows (LH and RH) 7 15 High Mounted Stoplamp, Brake Shift Interlock 8 25 Subwoofer, JBL Amplifier 9 10 Park and Turn Lamps, Side Marker Lamps, License Lamps, Stop Lamps 10 2 High Beam Indicator Electronic Cluster 11 15 Park Lamps 12 10 Remote Radio, Auxiliary Warning Lamp Module, Remote Keyless Entry (RKE) Module, Anti-Theft Controller Module, Radio Illumination 13 15 Radio, CD Disc Changer 14 5 Electronic Chromatic Mirror, Analog Cluster Indicator Lamps, Air Bag Module 15 — Not Used 16 15 Horns, Horn Relay Coil 17 15 Fog Lamps 18 25 Front Wiper Motor, Front Washer Pump, Wiper/Washer Relays 19 10 Generic Electronic Module (Pin 57), Electronic Instrument Cluster 20 25 Integrated Relay Control Module, Ignition Coil 21 10 Air Bag Module, Rear Window Defrost Relay, A/C Clutch, Temp Blend Door Actuator, Brake Shift Interlock 22 20 Rear Cigar Lighter, Power Plug 23 15 Multi-Function Switch 24 20 Rear Wiper Motor, Rear Washer Pump 25 10 Turn Signal Lamps, Instrument Cluster Turn Indicator 26 15 LH Aero Headlamp, Left and Right Trailer Stop/Turn/Hazard 27 15 Hazard Warning Lamps, Instrument Cluster Turn Indicator 28 15 Instrument Panel Cigar Lighter 29 15 Battery Saver Relay, Interior Lamp Control Relay, Interior Lamps, RH and LH Keyhole Lamps 30 25 Backup Lamps, Electronic Cluster 31 10 Rear Air Suspension 32 15 RH Aero Headlamp, Trailer Park Lamps 33 15 Anti-Lock Brake (ABS) Relay, Anti-Lock Brake (ABS) Module, Daytime Running Lamp (DRL) Module 34 30 One Touch Relay, LH Window Motor 35 15 Anti-Theft Controller Module 36 30 A/C Mode Switch 37 20 Door Lock Actuators, Memory Door Lock Relay 38 15 Heated Mirrors (LH and RH) 39 30 Auxiliary Blower Motor, Ref. Valve Solenoid 40 30 Window Motor (RH) 41 5 Autolamp Relay Coils, Autolamp Sensor 42 — — 43 — — 44 — —