The sensors are part of the latch assemblies. Sometimes just cleaning/lubing them will cure that problem. For the one that happens while turning, be sure that the latch is actually fully engaging - if not, you may have to make a striker adjustment. The latches of the rear doors are on the bottom.

 

make triple sure the rear door is completely closed. they can look closed, and act closed, and still trip the door ajar switch in the front door w/little movement while driving.
other than that, they are located in the latches. if you open the door and use a screw driver to manually latch the mechanism you will see the button of the switch under the latch arm. some guys lube them, but i find that the lube tends to attract even more dirt over time. i spray them with brake cleaner.
hold the inside handle open, use a screw driver to slip the latch arm back and forth rapidly, and spray brake clean in the hole underneath until the dome light starts workin properly again.


*edit, sheesh i type too slow for this board

 

Each striker is held by two screws (probably Torx) and are usually tightened like a **** from the factory. I find that loosening the screws slightly is better than loosening several turns because that can cause the striker to shift from its current adjustment position. Then you've lost your starting position. Better to back them off maybe 1/2 turn or so, then tap with a soft faced hammer to a new location. A little adjustment goes a long way.

 

I tried everyting to get mine working properly (lube. wd-40 etc) and nothing worked ..

I adjusted my door strikes and pushed them towards the iside of the cab just a few millimeters and the doors have NEVER given me a problem since.

Gumby is absolutly right tho ... check the door .. Ive gotten caught several times with the door ajar light on and I checked the back door and sure enough ... not latched properly but looked fine from the exterior ... nothing a good firm slamming of the door wont fix..

 

I just threw grease into the latches and havn't had the problem since..

 

theres a thread started by me that has pix and how to on how to change these with a link that someone found at rps i think. DO a search for door trigger location and i think it should come up from like 5 months a go

 

i took mine apart and used a q-tip and some brake cleaner.
been fine for about two years now.