Seat belts How to fasten the middle rear seat belt, it comes down from the roof of the car with 2 fastners, one must go into the spot which u have to unlock with the car key and then that would make the lap belt to be brought to other side, is that correct?

Preliminary Procedures
Remove the rear seat. Refer to Rear Seat Replacement.
Remove the left quarter lower trim panel. Refer to Quarter Lower Rear Trim Panel Replacement.


Preliminary Procedure
Remove the rear compartment floor stowage compartment tray. Refer to Rear Floor Trim Plate Replacement.
1
Rear Seat Nut (Qty: 6)
Caution: Refer to Fastener Caution in the Preface section.
Tip
Roll the seat forward enough to get access to the nut that attaches the center seat belt assembly to the floor.
Tighten
45 N·m (33 lb ft)
2
Rear Seat Bolt (Qty: 3)
Tip
• Adjust the seat forward or rearward to access the bolts.
• Remove the plastic trim pieces to gain access to the nuts.
Tighten
45 N·m (33 lb ft)
3
Rear Seat Assembly

Preliminary Procedures
Remove the quarter upper trim finish panel. Refer to Quarter Upper Trim Panel Replacement.
Remove the rear compartment trim panel. Refer to Rear Compartment Trim Panel Replacement.
Remove the floor trim plate. Refer to Rear Floor Trim Plate Replacement.
1
Quarter Lower Trim Finish Retainer (Qty: 2)
2
Quarter Lower Trim Finish Panel Assembly
Caution: Refer to Fastener Caution in the Preface section.
Procedure
Remove the cargo tie down loop anchor plates and bolts.
Remove the rear passenger seat belt guide.
Disconnect the rear passenger seat belt so that the trim panel can be removed around the seat belt. Refer to Rear Seat Belt Replacement.
Pull the trim panel toward the inside of the vehicle to disengage the retainers.
Tighten
9 N·m (80 lb in)
3
Quarter Lower Trim Finish Panel Retainer (Qty: 5)

You must remove the rear seat bottom and remove the bolt for the seat belt retractor, this will allow you to in jam the seat belt.

Rear Seat Replacement

Callout

Component Name
Notice: Refer to Fastener Notice in the Preface section.
Fastener Tightening Specifications: Refer to Fastener Tightening Specifications .
Preliminary Procedure Remove the rear compartment floor stowage compartment tray. Refer to Rear Floor Trim Plate Replacement .
1
Nut, Rear Seat (Qty: 6)
Tip
Roll the seat forward enough to get access to the nut that attaches the center seat belt assembly to the floor.
Tighten
45 N?·m (33 lb ft)
2
Bolt, Rear Seat (Qty: 3)
Tip

1. Adjust the seat forward or rearward to access the bolts.
2. Remove the plastic trim pieces to gain access to the nuts.

Tighten
45 N?·m (33 lb ft)
3
Rear Seat Assembly

if it was mistakenly not installed at the factory you can get one installed or more likely it is under the seat somewhere.

Some smaller cars have only 2 in the rear. The middle seat on 3 seat cars is only a lap belt , it may have fallen under the back seat.

Check to be sure it is the right belt and latch combination.
I believe you have 3 seat belts in the rear. The latch for the two side ( door) belts is not the same as the one in the middle.
VERY often, one of the latches will fall down in between the seat rest and the back rest of the seat, often from dis-use.
This happens on all cars.
You should have 3 latches on short straps in the middle of the rear seat.
Be blessed.

sensor on the seat belt fastener bad. Wiggle it to make it go off with the seat belt locked in place or change the sensor.

take it to your dealer and tell them the problem they should be able to fix/relpace the seat belt

middle seat belt shouldn't have anything to do with it. The seat locks down for stowage in the rear cargo area. you can pull the release handle on the back of the seat to release it back into the up position.

I'll begin by saying I'm surprised there isn't a 3rd belt on a bench seat, but I think you are entering dangerous territory. There is an immense amount of engineering, testing, and development involved in seat belt systems. They are anchored very securely at points that are reinforced and designed to withstand a human body being thrown against the belt, transferring the energy to the anchors of the belts. So, besides being beyond the scope of being possible to install by your average mechanic, I shudder to think of the legal angle. If u were to be involved in an accident, and someone was injured or worse in that seat wearing the added belt, the lawsuit possibilities are scary. Having said all this, check with your local dealer, maybe the Durango is set up somehow for an extra belt, but I've never heard it before.