To program the fob.....disconnect the battery. wait a bit. Reconnect and at every beep (5) press the remote button. If you have more than 1 remote press each one. If less than 5 press 1 remote for the other beeps. Simples......

 

My 1989 XJS convertible has been laid up for some years. I have now taken her out of mothballs and all works well except the alarm system which will not arm. Apparently there is a battery in the control unit which should be replaced. Where is this unit? I can not find it. And how do I replace the battery in it? Thanks

 

On mine '92 MY the battery sits below the alarm unit behind the right rear light. I have read that earlier cars might be below the seats. The battery for mine has not been available for 20 years.............works ok without it though.

 

seen here


alarmfix4.pdf