What modpack did you install?
Deadlyfoez can probably solder on gc ports so you can get into the recovery menu. You might be able to do it yourself if you get the gc ports, I don't know.
Don't give up, it would be good to know why you have this error 003, you would be the first none korean wii to have it.
Do you know how far into the wad install you got? What was the last wad to install?