No crank 2003 C240 v6 sedan
 

Hi everyone. I have a problem starting my car. 2003 C240 v6 base sedan. First off I all happened about a month ago. The engine wouldn't start however it was turning over just not starting. Now it won't turn over at all. I checked all of the fuses,good. I tested all of the relays,good. Changed the starter relay on a hunch, nothing. Pulled the alternator and battery and had tested at auto parts store,good. Changed the crankshaft position sensor,nothing. I noticed when I charged the battery it read 11.98v and when I installed it after one crank I tested it again and it read 6.20v. Bought and installed a new battery, nothing. Changed the oil, nothing. Bought a new key from Mercedes, still nothing. Looks like the trunk has been leaking water around the fuse panel area as well as a little bit under the hood. It sounds like I can hear the starter click once but now it doesn't click at all. My tranny went out on my truck now both of the vehicles we own are immobile.

Hello and welcome to the forum! Have you tried pulling the car's fault codes. Even if you didn't get a CEL, there are likely stored codes that should give you a good idea as to where the issue(s) are coming from.