4x4 light not coming on

It was working a few weeks ago. Feels like it is shifting into 4 hi and 4 lo, but no light on dash. Rear Diff locker light works. I replaced all the bulbs in the dash about a month ago so I doubt its burned out already. Where do I start?

 

Make sure you replaced the bulbs correctly

 

It was lighting up last week after bulb replacement.

 

It (bulb) may have come loose while on the trails. Check it.

Also, check your fuse, cab side - bottom left 20A.

 

Are you sure you didn’t cover the light w/ electrical tape? That’s how I fixed all those annoying lights of mine

 

I lost this cover on my truck about a week ago.
Thanks for posting this pic.

 

This helped me last winter. My front dif actuator wasn't getting the electrical signal from the TC to engage.