Can I get a French or German Passport without Parent Consent at 16?

I moved to the U.S. when I was ten years old to go live with my mom. Since then my passport as expired. I would now like to study abroad but need to get a new passport without loosing my existing French-German Citizenship. Therefore I cannot become a U.S. citizen and would need a french or german passport, but my mom would be the only one able to sign the passport, as my dad will not sign it. Is there anyway to get it with only one parent, or no parents at all at 16 years old?