How can I play European versions of games on my American Nintendo 64?

I have an American Nintendo 64 but I bought European games to play in French. I have the converter but it doesn’t work well.

For instance, The Legend of Zelda: Ocarina of Time only loads black and white and Conker’s Bad Fur Day doesn’t work at all.

What do I need do to play to make these games playable in French. Do you have any tips?