2001 mercedes benz c240 wont crank says PROD ON RADIO the electronic windows wont work and can't get the trunk open even with using the key or button I have replaced the battery with a brand new one and still nothing

 

Hello, I have worked on many cars from 1930 vintage Austins to 2015 Stuff, and they all have an Achilles heel or 2. Given the symptoms you tell us, two places to look are your neutral safety switch, and your ignition key switch. I am very suspicious of your key switch first. Another item to check on older engines in general, is if their is a possibility that your battery terminals or the wire connections to the terminals are not clean and lightly greased.