My light used to stay on so I just pulled the fuse!!! What about the dinging when you put your key in? Mine doesnt stop!

 

Just kidding.....

Could be that little button between the door and the cab. When you close your door it is pushed in. It may just need a bit of
WD-40. Some have also had problems with the door latch causing this. Again, just some WD-40.

Your truck thinks the door is open.

 

Don't feel bad. Mine "dings" when I open the door, key in the ignition or not.

 

There is no door button. To fix the problem just spray wd 40 under the door handle's for about 20 seconds on each side and the problem will go away

 

Not the same thing but I have a dinging problem too. So far they've replaced the GEM module and the ignition. Next week they are tracing all wiring between the two.

If the WD-40 trick doesn't work you might take it to your dealer.