2005 trailblazer makes a high pitched noise harder i push the gas higher heard it could be alternator because its output type sound right?

A high-pitched whine that increases with engine speed is a common symptom of a failing alternator, so you're on the right track. However, it's not a *definitive* diagnosis. Other components can make similar noises. To be sure, you should:

* Have the alternator tested: A qualified mechanic or auto parts store can test the alternator's output and identify if it's faulty. This is the most reliable way to determine if the alternator is the source of the noise.

* Check the serpentine belt: A worn or slipping serpentine belt can also create a high-pitched squeal, especially under load (when you accelerate). Inspect the belt for cracks, fraying, or glazing.

* Consider power steering pump: A failing power steering pump can sometimes make a high-pitched whine, especially when turning the steering wheel or at higher engine speeds.

* Listen carefully to the noise's location: Try to pinpoint where the sound is originating. This can help narrow down the possibilities. Is it definitely coming from near the alternator?

In short, while a failing alternator is a likely culprit given your description, a proper diagnosis requires a professional inspection or testing. Ignoring it could lead to a complete alternator failure, leaving you stranded.