Presume its a seperate black alarm fob? Try putting it right to the glass of the rear passenger doors at its nearest to the receiver. Sounds complex....top left of the window if you're on the drivers side....this is the only way mine will work, it has no distance at all.
Other than that, your receiver might be nakkered or batteries need replacing (presume you've checked that?)
Re yer Alarm................it is wired up to operate the central locking and not just to act as an Alarm
There`s also ways of turning bits of the alarm off or there is on mine i can make it autolock when the engines running or disable the central locking or self arm the immobiliser after 30 seconds etc etc
Or i could if i could find the instruction book i lost
The speedo will probably either be a fuse or the sender in the gearbox
According to my OH there should be a key in the glovebox somewhere that fits in a lock (Covered with a plastic cap) to the left of the boot release. Turn it anti-clockwise and it is supposed to de-activate the alarm system.
The alarm is OK guys. Needed a new battery in the plipper
Range is rubbish though.
The car wouldn't start because of a bad connection to the fuel pump....so Wrinx......you were right.......it wasn't the immobiliser