My daughter has a Tahoe that occasionally won't start without a jump. The battery is new and the alternator is good. Apparently she was told that the stock stereo is causing the battery to drain and that the Tahoe won't start if the stereo is removed; that she will need a new stereo either stock or aftermarket. Is this true that the stereo is needed for the Tahoe to start?

 

Never heard of that one. Who diagnosed this radio issue, dealer or independent ? Time for a second opinion from another dealer shop, weird electronic issues usually will not get solved at Joe Blow's garage.

 

This gets a little difficult for some folks to understand.
The vehicle has a network composed of many modules that communicate with one another. If for any reason there is a loss of communication among the modules , the code is set and some systems will prevent the vehicle from starting or preventing the system from going into sleep mode when shut down.thereby draining the battery.
A shop with a capable scan tool and sufficient knowledge can determine if any one of the modules is defective or falls a health check.