What is the part called that when the door closes goes into a slot to signal door is closed. is black and held on by 2 star bolts

Latch sequence in fixture is in closed position. This means the roundish shaped tab is down and blocking the door latch from entering the door.

If you look at the opposite door you will see that the latch resembles a slot for the post on the door sill to slide into when the door is closed. Your problem door will have that slot closed off by the latch.

Sometimes child safety lock-outs may be 1/2 way engaged and it gets the mechanism out of time. Or the spring which operates the latch breaks and the latch will not retract.

Make sure that the latch is doing what you want before you close the door, or you may be writing about what to do if the door won't open.

if it wont close, it could be the striker on the door jamb, should have 2 star bolts that take a star bit, you can loosen them , line them up with the door latch and re-tighten.

This is caused by the door not being properly adjusted to close all the way. When you open the door of the car there should be a stud or U-stud on the door jamb that the door latch latches to. It should be secured by star head bolts. Loosen the bolts and gradually, a little at a time, move the stud towards the inside the car until the light goes out. This will also ensure a proper weatherseal around the door, so there will be no road noise. Also, you will not lose any heat or air in your vehicle when you have the windows up, and running the heat or a/c.

Here's the solution: You might want to park it under a tree and tie a rope to the door to pull it up when loosened.
ADJUSTMENT Fig. 1: Door hinge adjustment
Fig. 2: Rear door hinge adjustment, F-350 Crew Cab
NOTE: Loosen the hinge-to-door bolts for lateral adjustment only. Loosen the hinge-to-body bolts for both lateral and vertical adjustment.

1. Determine which hinge bolts are to be loosened and back them out just enough to allow movement.
2. To move the door safely, use a padded prybar. When the door is in the proper position, tighten the bolts to 19–25 ft. lbs. (25.5–34.5 Nm) and check the door operation. There should be no binding or interference when the door is closed and opened.
3. Door closing adjustment can also be affected by the position of the lock striker plate. Loosen the striker plate bolts and move the striker plate just enough to permit proper closing and locking of the door.

loosen the 2 bolts on the floor catch slightly the close door GENTLY,then do bolts up again,push against closed door to see if you have too much gap,repeat until you are happy with results.easy close/no rattle...

You need to tighten the lock mech on the boot lid. this will close the boot just enough more to turn the light on. It's no biggy, you might need a star driver depending on bolt head. move it into the boot lid approx 4mm to start. then 1mm until 10mm. if no joy then it may be the sensor.
All the best
Ally A

If it's bolted on, check the top hinge bolt for being loose. there is an adjustment slot the bolt can slide in. It's a easy fix. If it's welded on check the top hinge weld behind the fender. Mine came apart at that spot (previos owner rewelded prior to my ownership). You will need to remove the fender to get in there to weld. The hinge is thicker than the sheet metal it's attached to.

Try adjusting the lower latch located on the floor (where the door locks) by loosing the 2 star shaped bolts and moving it a BIT (1mm or 2mm) forward and tightening them again.

First thing you do is take the door panel off, which pops off with a little pressure. The whole door panel comes out as a one piece, but the door handle stays on. After taking out the door panel, you will see the wire harness for the switch. You unplug this and the panel will separate from the door. There is a black plastic cover on top of the door held on by glue. Take your time to pull it off so that you don't rip it. Somewhat in the middle of the door on top of the plastic cover you will see a part of the motor with 2 bolts holding it. You will have to remove these bolts and complete taking black plastic cover off. Now, try to push the window back all the way up and get1 small hose clamp the size that the channel that the glass rides on. You might have to play with the switch on the front door to help get the window all the way back up, but to do this you will have to temporarily plug back in the rear window trim panel. Once it's up, unplug it again, while holding the window up in position. Put the clamp on and tighten. After that, drill a small hole right below clamp and put a sheet metal screw in to prevent clamp from slipping. This is the only way that you will save a lot of money, because the cost to repair this window would cost you close to $500.00. Granted, the window will stay fixed in the closed position. You can now put the door back together.

By 'Black bar' do you mean the window guide? If so, this is usually held in place at the bottom by a bolt or screw &, once removed, the guide should pull out downwards. The window should be closed. Your latch might have a black, anti-theft cover on the inside of the door which will also need to be removed.