Dependent vs. Indepenent sources!??... Can anyone give any insight into why you can't treat dependent sources as open circuits (dependent current sources), and why you can't treat dependent voltage sources as short circuits (dependent voltage sources)? I understand why it is the case for independent sources, but I just don't see why the same thinking isn't extended to dependent sources. For example, I have an example in my circuits II textbook where the Thevenin voltage is 0V at the terminals measured. The goal is to find the Thevenin resistance, but for whatever unexplained reason a test current of 1A is sent into the circuit to excite the dependent source's controlling component... why can't you read "through" them like any other source when they are deactivated; that is, when there controlling parameters are not excited. To put another way just to attempt to be more clear, if there is no input to the circuit; effectively "zeroing" the dependent sources, why can't you still read the equivalent resistance through the dependent sources like you do for ideal sources? I have not read any justification for this anywhere for this circuit analysis technique.