05 1.6tdci Bonnet lock mechanism / cautionary tale - mustangman
The Focus has a different bonnet locking method than usual. You swing the Ford badge at the front of the car aside & use the key.

A few days ago I attempted to open the bonnet. The key turned each way, but the bonnet stayed shut.
On looking through the grill, I could see that the plastic connecting rod had slipped off at the latch end.
No problem I thought, and tried to open it with a long screwdriver inserted just above the badge. I eventually opened it, but broke the plastic lock part in the process.

I trot along to Ford, they look at the part, consult the computer & inform me that I cannot buy the damaged part ( a plastic thing about the size of a cotton reel, should be cheap ) and I must but the whole lock driving mechanism. ( £25 )

Once this is supplied it consists of a short Bowden cable with the lock barrel at one end. I transferred the barrel & installed it.

However in talking to a mechanic I learnt that this is an ?upgraded? part to allow Ford to claim a level of compliance with Thatcham. Since it is effectively a short cable bent through an S curve, its quite stiff to turn even when new. He informed me that they fail occasionally mostly due to corrosion and / or the lock becoming stiff.
The fix is to cut the grill out of the car, cut the cable and peel it back until you can find enough to turn. If you are lucky the bonnet will open.

The moral being if you have this lock on your Focus, keep the bonnet lock and key barrel well lubricated. The cure could be very painful ££?s.
05 1.6tdci Bonnet lock mechanism / cautionary tale - Saltrampen
M
Mondeo mk 3 bonnet works in the same way. So I guess your advice may apply to Mondeo's as well?