have had an unknown bug develope. the cab lights stay on and do not time out and shutoff. key warning buzzer continues even when doors closed after shutting off engine and sitting. door ajar light comes on intermittently and the auto locks on doors does not work when this is on. Is there a relay switch controlling thes functions.
Sounds to me like the door jamb switch. Depending on the year of your truck it will either be at the front or the rear of the door opening on the cab. The way it works is when the door is open the button on the switch pops out and makes a ground contact which turns on your lights. When the door is closed it opens the circut and cuts off the ground contact. This will also turn the door ajar light and buzzer on and off. Something could be warn out or the switch is broken so the ground contact remains with the door closed. Find the switch and push the button in and out to see if your lights go on and off.
I've had the same problem on a 97 F-150. I fixed the problem very easily. Just spray some wd40 in the door latching mechanism on the side of the door when you open it. These get stuck and keep the switch from turning off.
