Annoying alarm dinging until van reaches 17mph

your door switches are probably dirty spray them with wd40 then scrub them with a tooth brush

TRY PLUGGING YOUR PASSENGER BELT IN.

That sounds like a poor earth/ wiring short to me!

one of the door ajar switches are sticking. needs to be put on the computer to find out which one. only other way is to go around and unplug the switches until your light shuts off.

first of all, you may have one or more door buttons that are bad. spray all door switches with a good spray lubricant and see if this helps. if not, find bad one and replace it. if door switches are bad door ajar light will think door is still open.

you have an open door, if all your doors close theres a door switch that on on indicating an open door, or door switch wire shorted to ground

You need a door pin switch in the drivers door. It must have gone bad, and this is very common. Usually it is hard to find out what door it is that is causing it, but in your case with the dinging bell- it thinks the drivers door is open- thast why the dome light stays on. The door pin switch is a little sensor that is installed on the latch assembly with a wire going to it and it is supposed to sence if the door is open or closed and turn the dome light on/off. you have to remove the door pannel and reach back to the latch. They are VERY tricky to get out without taking the whole latch assembly out. The part shouldnt be that expensive though.

one of the door/van loading door switches has failed it thinks a door is open so the the interior light stays on and the door open warning will ding the interior light should have a switch to disable it or take out the bulb but you cant stop the dinging until you find the faulty latch switch and fix it

you may have a broke wire in the door harness

ford puts a little switch in the door handle accessible only after the door panel is removed.dealer only part as far as i know...hope you have small hands and patience.removing the torx bits that hold the latch helps but note the actuator rods position(s).these bend easily.most switches are color coded,if you can find its connector ,.you can unplug it but this disables the dome lamp.