LT2 Equipment Group - Amp?

My '08 came with the LT2 Equipment Group [MP3 compatible 6-Disk CD Changer].  The original owner replaced the head with a Pioneer AVIC-Z2 unit.  It was working fine and sounded very nice when I got her early last year.  But now, I am not getting sound from my Front Passenger side Door or Rear Driver side Door speakers.  I am getting sound from both front tweeters up on windshield posts.

Did the LT2 come with an Amplifier under the center console? 
The screws on the side of the console are not easily to accessible with the seats in the way.

I'll probably check the speakers connections in the doors first but still wanted to know if there was an amplifier in this system

According to this site, https://www.autoblog.com/buy/2008-Chevrolet-Avalanche+1500/reviews/  no amp. The bose stereo with amp/sub starts with the 3LT and higher package. If you see bose labeling on the A-Pillar tweeters or otherwise, I'd then expect to find an amp. There are at least a couple very knowledgeable stereo guys on here, they'll likely have more info for you.


If it were me, since it affects more than 1 speaker, I'd start at the back of the head unit itself and test output from there.

I would suspect the original speakers in the truck... And they are likely blown. If you are hearing the tweeters then that makes it more likely that the speakers in the doors are blown.

The tweeters are wired in parallel with the door speakers so there is no separate outputs for them. Atleast with the older trucks anyhow. I am ASSUMING this is the same for newer trucks as well.

Rodney

Thanks for the input guys.  I'll start with checking the speakers and connections in the door. 
Now to search for instructions removing the door panels to access the speakers.

So you're right. I pulled one speaker and it not working at all.  Now I'm shopping for replacements.

I'm thinking 4 decent speakers for about ~$200 or less .
Or put less mulah in the speakers and add powered subwoofer for ~$300 total.

Opinions?

I assume that there is a crossover somewhere and If I just use a 2-way or a 3-Way speaker with the stock tweeters in the pillars, the tweeters built into the speakers will just not play. 

Is that correct?

If you?re looking for a coaxial not component I personally run Kicker CSC 6.5? they sound great in my opinion (I push them with an el cheapo boss amp) I think they were around $60 a pair. Hope this helps.

I also disconnected factory tweeter in my 03 non Bose because the coaxial already has tweeters in it probably more powerful and clearer than factory but don?t quote me on it.