The metaphor "blind leading the blind" is taken from the Bible. So it exists in almost all languages. In German the best known translation is the translation of Martin Luther saying (Mt 15,14): "Lasset sie fahren, Sie sind blind, und Blindeleiter. Wenn aber ein Blinder den anderen leitet, so fallen sie beide in die Gruben." or (Lk 6,39): "Und er saget ihnen ein Gleichnis: Mag auch ein Blinder einem Blinden den Weg weisen? Werden sie nicht alle beide in die Gruben fallen?" In English you would probably prefer to use the well know King James Translation. There the citations read (Mt 15,14): "Let them alone: they be blind leader of the blind. And if the blind leads the blind, both shall fall into the ditch." or (Lk 6,39): "And he spake a parable unto them. Can the blind lead the blind? shall they not both fall into the ditch?"

When a blind is leading the blind "Ein Blinder fuehrt einen einen Blinden" that means that the business ends up in ruin.

Hello Ann, An equivalent or similar idiom might be : "Der Blinde erklärt dem Einäugigen die Farben." The blind explains the colors to the one-eyed man. It means somebody tries to explain something he knows nothing about to someone who knows just a little about it.

Es gibt "Ein Blinder, der einen Lahmen führt." = a blind leading a lame. Meaning that someone who isn't too qualified helps someone who's not capable doing something on his own. But together they would accomplish nothing. führen = to lead, to conduct, to direct, to pilot, to shepherd...