I have a broken peltier since the fan is not working.
What is the simplest way if the fan not working,
the current to peltier device will automaticly cut off?

Sorry for my english,
I am from Indonesia.

Best regards

 

A temperature probe on the cold side can detect a fan failure. (I suppose it can be on either side, but the ones I have seen are usually on the cold side.) If the hot side of the peltier is not cooled by the fan, the cool side of the peltier will not stay cool. Then you would operate a thermostatic switch to turn off the peltier if it's hot.

 

A temperature probe on the cold side can detect a fan failure. (I suppose it can be on either side, but the ones I have seen are usually on the cold side.) If the hot side of the peltier is not cooled by the fan, the cool side of the peltier will not stay cool. Then you would operate a thermostatic switch to turn off the peltier if it's hot.

I try this scheme, but not working
Please someone help me?

 

What did you want that circuit to do? Is "M" the fan? The relay will always be energized as long as the motor winding has continuity. It will not change if the motor stalls.