Interior lights and rear number plate light come on when I lock my 316i

[colin rowe]

Hi All.
My first post, hope this is the right place to post, and that someone can help me out.
I picked up a 97 316i estate for my wife on Sunday. Lovely car, in pristine condition. Everything was going well untill I made up a second keyring, for my own use. The car was supplied with the key and remote fob that was in the ignition + a spare fob and 3 additional keys. One of the keys was a genuine BMW key, the other 2 were grey in colour. I made up my keyring using the spare remote fob and one of the grey coloured keys. When I tried it, it took a couple of presses to unlock the car, car started fine, and away I went. I returned home at dusk and locked the car. The car locked but the dash lights (everything but the interior lights came on), the rear number plate light also came on. I hit the unlock button, and the car unlocked, and all the lights went out. I tried locking the car with the key, locked fine but all the above mentioned lights came on again. left it like this to see if the lights would go out, and after about 10 minutes the alarm went off. It does exactly the same now even if I use the original key and remote, wasnt doing this until I tried the different fob and key. Have I messed up the coding, if so, can I sort it myself ?
Thanks.
Colin
PS. Its sitting in the drive at the moment, unlocked, with an Isuzu Trooper parked behind it