My interior lights wont shut off

Probably the HDM - headlamp driver module .
The headlamp driver module (HDM) is an electronic module that provides electrical power to the vehicle low beam headlamps. The HDM is controlled by a pulse width modulated (PWM) ground signal from the body control module (BCM). The BCM determines the desired lamp intensity using the ambient light sensor, multifunction switch and the park brake switch as inputs. In general, the HDM will operate in 1 of 3 modes:
• Reduced Intensity Mode: This mode is used by features that do not require or allow maximum low beam headlamp intensity such as daytime running lights (DRL) (nominal: 85% duty cycle).
• Full Intensity Mode: This mode is used by features that require full low beam headlamp intensity such as low beam headlamp operation in manual or auto modes (nominal: 100% duty cycle).
• Off Mode: This is the default mode of the system that will occur when none of the features described above are active. The BCM will deactivate its PWM output (0% duty cycle) during this mode.

HDM is a relay located in the under hood fuse box . #46

Low beam's don't work , how about high beams . Low beam relay is turned on by the BCM - body control module , headlamp switch is a input to the BCM . Your best bet mite be to take it to a qualified repair shop , rather then guessing an replacing parts you don't need . Hooking up a scan tool an checking for DTC'S - diagnostic trouble codes should have been the first step before replacing parts .
The headlamp driver module (HDM) is an electronic module that provides electrical power to the vehicle low beam headlamps. The HDM is controlled by a pulse width modulated (PWM) ground signal from the body control module (BCM). The BCM determines the desired lamp intensity using the ambient light sensor, multifunction switch , wiper motor, and the park brake switch as inputs. In general, the HDM will operate in one of three modes:
• Reduced Intensity Mode: This mode is used by features that do not require or allow maximum low beam headlamp intensity such as daytime running lights (DRL) (nominal: 81% duty cycle).
• Full Intensity Mode: This mode is used by features that require full low beam headlamp intensity such as low beam headlamp operation in manual, wiper activated headlamp (WAH), or auto modes (nominal: 100% duty cycle).
• Off Mode: This is the default mode of the system that will occur when none of the features described above are active. The BCM will deactivate its PWM output (0% duty cycle) during this mode.

Chevy Trailblazer headlights don work HDM input output testing YouTube

Low beams don't work ??????? But high beams do ????? DRL - daytime running lamps ?

HDM relay # 46 low beam relay , under hood fuse box.

The headlamp driver module (HDM) is an electronic module that provides electrical power to the vehicle low beam headlamps. The HDM is controlled by a pulse width modulated (PWM) ground signal from the body control module (BCM). The BCM determines the desired lamp intensity using the ambient light sensor, multifunction switch and the park brake switch as inputs. In general, the HDM will operate in 1 of 3 modes:
?€¢
Reduced Intensity Mode: This mode is used by features that do not require or allow maximum low beam headlamp intensity such as daytime running lights (DRL) (nominal: 85% duty cycle).

?€¢
Full Intensity Mode: This mode is used by features that require full low beam headlamp intensity such as low beam headlamp operation in manual or auto modes (nominal: 100% duty cycle).

?€¢
Off Mode: This is the default mode of the system that will occur when none of the features described above are active. The BCM will deactivate its PWM output (0% duty cycle) during this mode.

The normal battery voltage input to the HDM must be between 6 and 16 volts DC to operate. Any deviation to these values could cause improper operation.
Major components of this system are the BCM, HDM, ambient light sensor, multifunction switch, park brake switch and low beam headlamps.
DTC B2575 Headlamp Control Circuit
When the body control module (BCM) senses a request for headlamp or daytime running lamp (DRL) illumination, the BCM sends a pulse width modulated (PWM) ground signal to the low beam headlamp driver module through the low beam headlamp driver module control circuit. The low beam headlamp driver module will illuminate the headlamps, adjusting the intensity based on the PWM signal received
You best bet is to take your vehicle to a ASE certified repair shop or the dealer >

Did you check the fuse's an HDM relay #46 in the under hood fuse / relay box ?
Headlamps
The headlamp driver module (HDM) is an electronic module that provides electrical power to the vehicle low beam headlamps. The HDM is controlled by a pulse width modulated (PWM) ground signal from the body control module (BCM). The BCM determines the lamp intensity using the ambient light sensor, multifunction switch and the park brake switch as inputs. In general, the HDM will operate in 1 of 3 modes:
?€¢
Reduced Intensity Mode: This mode is used by features that do not require or allow maximum low beam headlamp intensity such as daytime running lights (DRL) (nominal: 85% duty cycle).

?€¢
Full Intensity Mode: This mode is used by features that require full low beam headlamp intensity such as low beam headlamp operation in manual or auto modes (nominal: 100% duty cycle).

?€¢
Off Mode: This is the default mode of the system that will occur when none of the features described above are active. The BCM will deactivate its PWM output (0% duty cycle) during this mode.

Before you replace the #46 HDM relay (in the fuse block under the hood) try exchanging it with the #45 cooling fan relay and see if your low beam lights work. If they do, the HDM relay (actually solid state module, not a relay) is bad.

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The problem with the headlights is a common one and it is in the low beam relay.; In the under hood fuse panel, locate the HDM relay, swap this relay with the FAN relay next to it. If the lights stay on, replace the relay. This is a solid state relay, so make sure to get the same part number.

{: ) I wonder how you checked the fuses and the bulbs. Did you check also the HDM fuse 15amp and the HDM relay both at the underhood fuseblock? Turn on the low beam and check for 12v at the LO beam fuses. If there is voltage at the fuses but the low beam ok bulbs won't light, then there's a wiring issue from your fuseblock going to the bulbs.
But if no voltages on the LO fuses when the low beam is switched on, then the problem could be on the HDM fuse or relay, the headlamp switch, the BCM, or even the fuseblock.

switch your #45 relay for cooling with #46 for HDM. I just had this problem with my blazer and we just fixed it but doing that.