Nintendont not working on Wii, but works on Wii U

[MetalGearPearl]

Hi, I have a problem and I have no idea how to fix it, I've had this problem for a long time.
As the title says, Nintendont works perfectly on my Wii U and Dolphin, but I want to use it on my old Wii to use my Memory Cards, but my problem is that I can't play my dumps from the Wii, I've looked in different tutorials and it's not any of my problems of renaming the game wrong to game.iso, or anything like that.
I've used the same SD card from my Wii on my Wii U and it work fine, but when I try again on my Wii I get the problem that no games are detected.

What can I do to solve this? Thanks.