Interior Lock controls and not working
 

I have a new used 2003 CL500 with 118K miles. I have only owned for a couple of weeks. Seems to be in good shape with a few small issues. I cannot lock or unlock doors or open trunk with interior controls. I have to manually lock drivers door with the key but it doesn't lock passenger door so I have to do that manually. Key FOB sends a signal but doors and trunk unresponsive. Any suggestions I can make to my mechanic.

A second issue involves one of the front headlamps. Not working and a replacement bulb did not fix the problem (bought a genuine bulb for this model Mercedes). First, suggestions as to what the problem may be? Second, what are the most economical bulbs to purchase? I am not trying to be cheap, but I do not want to be unduly extravagant either. This is my first Mercedes, so be nice.

About the key fob: I just ran into that issue with my '02 CL500 Sports Coupe. My mechanic suspected it had something to do with the anti-theft system because the fob would also not engage in the ignition while not operating the locks or trunk-- this happened periodically, then set itself right. So, i took it to a dealership and the guy determined a faulty ignition. They changed it and now my door locks do not work at all AND I'm having issues with the front windows not closing. i only got my car back today after being in the shop for 2 weeks. I hope the issue with the windiows will resolve themselves like other issues which occur when disconnecting the battery-- like the sunroof not responding as it should or the side view mirrors not closing in and opening along with the door.

It's a pain owning an older Mercedes....a pain in the wallet!