My 2007 2.0 diesel C30 recently "died" after a few warning messages flashed up in quick succession - now the display just says 'immobiliser' and the computer refuses to let the car start.

Further inspection shows the fusebox to be full of water (probably leaking from the sunroof drainage pipes). The fusebox appears to be knackered and my local Volvo dealer wants £980 for supply and fitting a new one. No that's not a misprint - nine hundred and eighty pounds! And I suspect that amount won't include the dreaded VAT.

The garage where the Volvo now resides (!?) have tried to fit a secondhand fusebox (which includes some kind of ECU) but they can't get it to work.

I can fix the leak but does anyone have any hints, advice, suggestions on getting the car to burst back into life?