Gear Shift Light will not illuminate

I just bought a used 2003 TL S-Type. I drove it for the first time at night, and I noticed the gear shift did not light up when the lights were on. All of the other instrument panel lights work fine. I check the manual for all of the fuses that it could be, but none were specifically for the gear shift itself. I checked a few of the fuses that may have been part of the gear shift, but they were all fine. I also had the dimmer set to the highest setting.

Any suggestion on what may be the cause and how to fix this?