1999 xlt can't turn motor off..

[bobofbuenapark]

My 1999 Ford Expedition XLT it will not shut off unless you disconnect battery and disconnect the wiring harness on the firewall. Turning the ignition switch to the off position is unless. It continues to run all the time. No one knows what the problem is an it has been in the shop for over a month. They changed the fuse box. And looked at all the usual suspects but nothing please help

 

[stamp11127]

You can stop the motor by pulling the fuse for the fuel pump.

The first part I would check would be the ignition switch. It shouldn't be difficult to locate the source of the problem - the pcm needs power in order to run the engine, the fuel pump needs power also. Both are common to the ignition switch once it is turned to the run position.
Simple diagnostic test would determine if power is still supplied to the pcm from the switch once it is turned off.

 

[bobofbuenapark]

motor wont shut off...

I am sorry we have 2 Expeditions the one with this issue is a 2003. Would that be the same solution or would I want to look at some thing else?

 

[stamp11127]

Yes it should be similar.