I found a much easier solution: There is a free app called LabTick that allows you to adjust the keyboard illumination regardless of input from the ALS.
Do you know what each wire from the ALS does? Previous owner broke the connector socket off the logic board; now the computer thinks it’s always in maximum ambient light, so the keyboard backlight is disabled. Wondering if I can hardwire 2 pins together on the logic board to make it think it’s in minimum ambient light, so I can control the keyboard backlight manually. Thanks!!