So, I have problems with both keys for my Mk3 Focus (65 plate 1L Ecoboost Titanium with KeyFree).

The problem with the main key is simple enough - it's in about 10 pieces. The Mrs managed to trap it in a door. My spare is intact but it's never worked remotely so I have to take the little manual key out and use that to get in. It's not a flat battery, I've replaced that and occasionally it will manage to unlock the car when I'm standing next to it, or sometimes it's so weak I have to put it in the little secret spot in order to start the engine.

I could really do with not paying hundreds of pounds to a specialist auto locksmith right now, so are there any cheaper alternatives to replace the shattered one? The circuitboard looks to be intact so could I buy a shell of a key and transplant it in? If I do need professional help, what's the going rate and is there anything I should look out for?

Any help greatly appreciated - juggling a baby and a bag of shopping while fiddling with the manual key today was not fun.

Thanks

Hi, the circuit board of your smashed key looks still to be ok (hard to tell from the photo). You can buy a replacment keyfob off eBay for less than £20. Then just transfer the circuit board and the key blade over and you should be good to go.

The mostly non-working key must be programmed in to the car for it to work now and then. Buy a good quality Duracell battery from an electrical shop (Not Pound Land) and replace the battery in your key (yes, I know you have already done it, but please try again). There are a lot of problems with keys caused by poor quality batteries, and most times the keyfobs are fine.

Thanks, I'll try that. The circuitboard in the smashed key does look to be intact, no visible damage as far as I can tell. The other key has been getting worse over the past few days - now when I get in the car, put the key back together and put it in the centre console special spot the timer will still be going and the alarm will sound for a fraction of a second. There doesn't seem to be any way to stop it.

What about swapping the circuit board from the smashed up key into the intact one that doesn't work, or in other words take the good bits from each (case and put in the working components) to make one good one?  Then make sure you don't smash that one up or lose it!