325i auto lock/unlock

the drivers side door automatic lock/unlock with the key does not work. i have to go to the passenger side to unlock the doors. turning the key locks and unlocks the doors. the passenger door is the only one that works. even the trunk does not unlock (used to). is this just a loose wire or am i looking at a big expense? If i install an aftermarket car alarm, will that fix the problem? Is there any way to disable the auto lock/unlock to where I can just use the key like normal, or push/pull up on the door lock?

Thanks for your help.

How old is your 325i? My Brandnew 318i has the similar problem for two weeks. I put it to dealer for fix it. The problem was happened in some ocurrances, not 100%. They told me that it may be some program problem.

It's a 95 convertible.