'83 Mercedes 240D quick problems.

[keredchang]

Where can I find the fuse that is directly behind the radio? This fuse is not similar to the rest of the fuses and lies directly in the radio itself.

Also, where can I purchase/find the bulb that lights up my gearbox? Is it available at any ordinary electronics store or must I buy it at a more specific location?

Lastly, while my car was running, I tried unlocking my doors. One of the locks (specifically the rear right) wouldn't rise with the rest. Instead, there was a loud grinding/vibrating noise that was coming from the engine area. Is this a sign of a leak in one of the hoses, and it the noise was from the hose struggling to produce air pressure? A couple minutes later everything locked fine, but I was just worried.

Thanks.