Randomly enable objects, need help

Hello, i have spinning wheel, when it’s stops, random character should be enabled.
But when i execute the script, always enables only first character.
Here is the sample:

for(int i = 1; i < SaveLoadData.instance.characters.Length; i++) {
    SaveLoadData.instance.characters [Random.Range(1, i)] = true;
}

Thank you.

Check Random.Range; It returns a random integer number between min [inclusive] and max [exclusive]