hiya and help please lol

hey guys n gals hope your all well. hope you all had a good xmas and have a fantastic new year

quick question the central locking not working on my 1995 p38 range i've tried to re-syncronize it but still not working, i am using key 2 as we've replaced batteries in both keys but key 1 and it's not working.

I've been using the key to lock and unlock since we brought the truck back in july last year but we are looking to sell and wanted to get this working (cheap as possible) as abit of an added bonus lol

so any help is gratfully received

First place to look is the RF receiver in the boot under the trim on the drivers side, it may have been disconnected due to interferance flattening the car battery.