New AVIC-Z120BT mounted and works, except now my climate controls are frakked

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2002.5 Mazda Protege ES
Ok, so I had a local kid who works at an audio shop do my AVIC install and after the fourth try he finally got it right. Other than a little engine hum/buzz, everything works.

Unfortunately, now my temperature controls don't work (no matter what I get cold air) and the lighting on the mode (vent, footwell, defrost) is no longer lit at night.

Two questions: 1) how do I get rid of the engine buzz/hum? grounding kit? and 2) how involved is the climate control fix? am I better off just taking it to the dealer? I'm "handy" but limited in my skills, otherwise I would have installed my own stereo.
 
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