How can I find my iPhone if it is dead?

The phone must be turned on and connected to the internet in order to send a signal from its location. Check this link...

If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support

If the battery is dead on your iPhone then it is not going to be able to connect to the internet to report its location. This calls for a search the old fashioned physical way.

Axel F.

No matter how many times you post this question, the answer will not change!