My instrumental lights in my dash light up, but the lights controlled by the dimmer do not work. I have checked fuse #19 and ensured that it still works. Do I need to buy a new dimmer?

 

It's quite possible.

The dimmer has a plug in the back of it and it pops our from behind. Not sure how difficult it will be for you to reach up behind the dash to pop it out so you can unplug it.

After that, it's a rheostat. A potentiometer with it's middle leg connected to one of it's end legs.

If you measure resistance on the two connectors of the dimmer, you should read a change in resistance as you spin the dimmer. If resistance stays the same regardless of the dimmer spinner position, the dimmer is bad.

 

Okay, I'll have to test it