Bought a 2011 Yukon XL : Need Advice on The Current Audio Mess

[MEGADOPE]

Whats up guys,

 

I recently bought a 2011 Yukon XL. The guy that I bought it off put a 10" screen , Double Din Unit from china in the thing.

It was wired to the original Bose Blows system. There is also the stock DVD player in the roof for kids.

 

I'm trying to diagnose wtf is going in here before I rip everything apart.

 

1st ... Only the front door speakers and tweeters were working. 

I asked him about that and he said "I turned off the rear speakers to the kids could watch DVD's with the back speakers."

 

2nd ... after a recent computer reading at the inspection sticker place , a couple days later one of the rear door speakers

starting randomly buzzing and pulsing around 40hz into a distortion loop.

I disconnected that door speaker. Then the loop reappeared in a rear tweeter i disconnected that. Now its in the front door speaker.

 

With my intermediate knowledge of car audio systems im guessing its some kind of ground loop?

Anyone have experience with a stock system similar to this?

 

*... for the moment , since i dont have enough money saved up , i'm hoping to salvage the bose system thats already installed

however I want to add my sub to it.

 

My plan is to say fuck it , rip out the bose amp , install my old 4 channel amp and hopefully run that to the old bose front door speakers.

Then bridge channel's 3 and 4 to my sub just to get me by for the moment. I dont need the back door speakers at the moment.

 

Is it even possible to rewire the bose door speakers to run with my after market amp or should I just buy new door speakers on the Credit Card?

 

thanks