It is said that if the ariel wire inside the steering column cowl drops away, the key sensor won't be recognised. I believed though that the car wouldn't turn over if this was the case. But the position of the wire inside the cowl is worth checking.
Fuses - mine is 2005 so the position of the boxes may vary, but........
Fuse No7 of 8 under the bonnet is 20A "Engine"
Fuses 1,2 and 3 under the dash (block of 20) are 15A "Engine" fuses.
