Automatic Transmission Backlight Bulb/Socket Doesn't Work

New Taco owner here. Well, actually it's my son's truck. Among other things, we've been upgrading the interior bulbs to LEDs. I was trying to replace the automatic transmission shifter backlight bulb and have determined that the circuit isn't working. I connected my multimeter to it and only got 6.1 volts. Neither a new LED nor a type 74 incandescent bulb would produce any light. Does anyone have an idea as to what may be going on or where I could start looking? Truck is an '05 Double Cab Prerunner 2WD V6. Big thanks!

 

Is the rheostat turned down? (dim)

 

I would chase the wire back to the fuse looking for problems with the wiring .
https://www.tacomaworld.com/threads/how-to-replace-your-automatic-shifter-indicator-lamp.22332/

 

Thanks for the tips and feedback.

The rheostat isn't turned down too much (other dash lights on the HVAC control panel) are visible. I'll turn it up to full power and re-test.

Please tell me that there isn't a separate fuse just for that light. I'll trace the wires at some point.

 

One fuse for dash illumination...