Any help would be appreciated, to lock and unlock my 2005 forester XT I have to put my key right next to the windscreen for it to work, I have changed the battery in my key but still cant be opened / locked from any distance over 6 inches away. Any ideas please.

Could be weak key fob so worth trying another, also worth looking at antenna on car & seeing if can be positioned better or extended to improve the range.

What alarm is it ? Sigma !

If you don't have a spare fob worth getting one & if Sigma alarm with keypad worth checking you have a working pin code as easy change code & add extra remotes while you have a working remote but not so easy or free without.

Is it a cat 1 system?...if so the antenna wire will be wrapped around the heater motor. under passenger side behind the glovebox top left.