the central locking wont work opel astra 99?

Turn ignition on ( dash lights on but do not start engine).
Push lock button on key fob.
Doors should lock and unlock.
You may need to push the button a few times for it to work.
Remote should now function as normal.

Other possible problems are loose or broken battery connection in fob or dry joint on fob PCB.
Most auto locksmiths, and some garages, will have a key tester, or you can buy your own if you like gadgets. It's just a radio and infra-red reciever tuned to the common key frequencies.

http://www.justoffbase.co.uk/IR-RF-Key-Fob-Tester-Sealey-VS921

gibby
July 2009