I have a Ford AU 99 manual - the one with the smartshield.
It stopped deactivating, was advised to reco the BEM - have done this.
Key has been checked that the code is still working.
Ring reader thing on steering coloum has been replaced.
Also had an auto elec out to have a lock but unable to find the cause.

Seeking any other ideas?

Verify interior light is working
Check all fuses with a test light
Scan for codes
If you have 2 keys try other key
How did you check the key was working. note.remote has nothing to do with starting vehicle
Did auto electrician do a parameter reset
Does light on dash flash with key off
When you first turn key on does light flash any code

If you change BEM 2 keys need to be programmed and a parameter reset needs to be carried out

We had the chip checked in key at specialist lock business.
We only have the one key and no remote.
The light flashes normally without key or in off position.
At start when move to On it just starts flashing erratically.
Not sure about the parameter test.
Interior light fine.

And BEM was our one just reconditioned.
No codes were read by our mechanic when this was first an intermittent issue.

Are you still having problems with this vehicle

Suggest checking with auto electrician if he tried to carry out a parameter reset if he doesn’t seem to know what you mean try a different auto electrician

Where your key ring connects in the key itself does the slot go half way or all the way across
half way if it is smart shield all the way across if smart lock
Smart lock up until 6/99 iirc which requires you to leave key on for a hour
Smart shield requires 2keys and a scan tool to program plus do a parameter reset