The led should not be solid from the moment you put the battery on. It should flash, then go solid as you turn the ignition to run, then go out completely.

What sort of led have you used ? If not using the mondeo clock.
It should be pre wired with a resister. It should NOT be a flashing led, the ecu does that bit.

I wouldn't worry about it cranking or not untill you have the immobiliser sussed.