Why won't engine shut down when turn key off

I’m sorry for the delay. You most likely have this figured out or a garage has remedied this for you at this point.

I would need a little more detail to answer this question with 100% certainty but based on your brief description, this would most likely mean the ignition switch is faulty. Vehicle electrical issues are not easy to troubleshoot but in this case the ignition switch is where you would want to begin. I’m afraid the only way to shut the Durango off while in this state would be to very carefully disconnect the negative battery cable.

The key allows the tumbler to turn to specific positions for Accessory, Off, On and Start. Each position of the key engages or allows specific electrical circuits to make a connection within the ignition switch. There are plastic components within the ignition switch that can physically break as well as electrical contacts that can become dirty or worn out to the point where they do not complete the circuit for the desired key position. The fix in this scenario is to replace the ignition switch. Please take extreme care and follow a service manual or extensive guide before attempting to replace this part on your own. Always disconnect the battery first and follow all safety precautions. Often times, you may be required to disconnect the steering wheel air bag which can go off if you do not carefully follow the instructions.

On occasion, the tumbler that the key is inserted into and allows the key to turn/rotate to it’s specific positions could be at fault. Sometimes it will break or wear to the point where the key does not turn once inserted, could stick in place, or will not turn quite far enough for a certain key position due to wear.

Anything beyond this is likely for someone who is comfortable with vehicle wiring. You would have to trace your ignition wires to look hard for corrosion, pinches, breaks, cuts, splits, etc. and repair as necessary. I’ve had a few experiences where mice were at fault… It’s no fun when you replace a brake light bulb to find out that it still doesn’t work, then after a little digging you find the mice have chewed into or through the wiring in a place that is very difficult to access.

Hope this helps!