My brother just bought a 94 xjsc a few weeks ago after driving it for 2 weeks the fuel pump died. After changing out the fuel pump the car wouldn't start so apparently the fuel pumps won't start so we put a cable from the fuel pump to the battery and it ran. After 5 days of driving the alarm suddenly went off while going down the road. Since then the alarm will go off if the battery is plugged in for more than 3 seconds, bought a remote for alarm since previous owner lost his but before car can go into learning mode the alarm goes off. Any ideas?

 

The valet button was missing also