On the Audio Panel, there is a knob (the VOR\ADF Receiver Selector) that has VOR L R ADF L R (#5 on the attached image), select the VOR you want to use the IDENT on, then press (click on) the Reciever Button to the right (there is a line running from the VOR\ADF Receiver Selector to the Reciever Button) an a green light with come on.

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