98' 740i door lock issues

Just bought a 98' 740i and the only way I can lock/unlock the doors is through the trunk lock. Also, my central locking system button does not work. Any ideas!

"... Any ideas?"
Well, a few. I used to have an '89 325iS that had pretty much had the same problem except that it was only drivers door that didn't work, so I could walk to the trunk or I could walk to the passenger's door to lock up. On my car, the door would lock/unlock electrically from the trunk but would not lock via the key at the door. I tracked it down to a broken lock mechanism on the driver's door. After taking off the door trim panel I could see the mechanical problem but I couldn't get it kludged up to work through the very limited access space.

One day I was at one of those aftermarket shops for stereos and they had an offer for wireless entry for $50 installed so I had them do it. Nothing fancy, one button to lock, one button to unlock and didn't tie in with the car's alarm system or anything. This is a bit kludgy for your newer and nicer '98 740i, but it is an option.

On your car I'd remove the trim panels and verify the problem and then bite the bullet and pay for genuine parts. Try to avoid the dealer for labor if you can't do it yourself but I'd make sure it's tied in with the original factory alarm, etc.

Thanks for your time in responding. I will try your second option and use your first as a fall back.