2006 CHEV SILERADO 5.3LT 4 DOOR 4W DRIVE DRIVER DOOR SENSOR

generally is the door sensor dirty or disconnected

alarm will obviously sound because the anti theft device thinks door is open...maybe it doesn't think ...it mis detects
check the door light switch and how it is affected by closing opening of door. look at what happens at the contact point.
It may be something mechanical, or something electronic/electrical
empirical testing should reveal the answer

There is a plunger switch inside the door. It may be stuck in or bent in.

Can you tape a coin or two onto the door at the spot that hits the light switch? If not, just remove the bulbs.

its a switch with a rubber cover on it you can push it in and out, may just need a clean with some wd40 as they rarely go unless water is getting in the back of them.

Usually the solution to this problem is to use a good penetrating oil and spray HEAVILY the latch mechanism (both doors), let it soak in, and open/close the door 15-20 times-the sensor is in the door and it gets hung up, spraying lubricant on the latches frees it up.

I am a master ford tech and see this concern weekly ! more often then not its a dirty door ajar switch which is located in the latch in the door. get yourself a can of brake cleaner with a straw and a can of wd-40 from a parts store and install the straw in the brake clean now spray the latch liberally then close and open the door six to eight times,next spray the latch with the wd-40 liberally then close and open the door six to eight times, this more often then not will fix the issue. if not you may have a bad switch or a wire broken where the wires past between the body and the door (near the hinges) hope this helps

I think that there is micro switch inside the door on the dor lock mechanism.

the actuator for the dome light is actually located inside the lock mechanism. Have you checked to make sure the dome light override button is in the out position?

The drivers side door latch is bad. Just replaced one in my daughters 99 beetle. $184 dealer part. same thing no lights then alarm will mgo off for no reason, lights will come on at random times while driving, no chime when key is in.