a case of the blind leading the blind

A situation in which an incompetent person tries to guide or teach those who are equally incompetent. That project stalled as soon as it became a case of the blind leading the blind—no one knew what they were doing! Don't ask me to tutor someone in algebra because it would be a case of the blind leading the blind.

case of the blind leading the blind

Fig. a situation where people who don't know how to do something try to teach other people. Tom doesn't know anything about cars, but he's trying to teach Sally how to change the oil. It's a case of the blind leading the blind. When I tried to show Mary how to use a computer, it was a case of the blind leading the blind.