[chrstphr81620]

After scouring the web, I couldn't find a great How-To on bypassing the factory amp :banghead: . There are about 6 threads that cover all of it in sections, but it was a little annoying hopping back and forth trying to figure out everything. SO I'm gonna throw all of this stuff into one thread. (I'm sure as soon as I post this, someone is going to post a link to some great instructions, but whatever)

This instruction is to replace factory Delco stereo that you don't want anymore considering you haven't owned a CD since Brittany Spear's was #1 on TRL.

Image uploading. Refresh page to view

I've wired in a Kenwood BT958HD. Bluetooth, AUX, 2x USB. I'm not going tell you anything about installing the Head Unit, considering there are a billion how-to's online, this write-up is going to focus on our special amp.

Image uploading. Refresh page to view

Why bypass the amp? Well, everyone that's installed an aftermarket Head unit, has found that the rear door speakers stop working. The factory amp ONLY powers the two rears, so you should already have the two 6x4" tweeters on each tower working before this process. And pretty much every In-Dash stereo sold nowadays has a built in amp that should have no problem powering all of your speakers.

First off: Locating the amp:

The amp is sitting behind the kick panel just behind the driver' seat. It's easiest if you remove the first row seat so that you have room to work. It should pop right off without any tools, besides one small phillips just inside the drivers door panel. You'll have to unplug the little running light for the drivers door jam. You'll find the Amp in between the Gas Fill, and the rear wheel well.

Image uploading. Refresh page to view

Image uploading. Refresh page to view

You can unplug the wiring harness and toss the amp out, You won't be needing it anymore.

Image uploading. Refresh page to view

Step Two: Splicing the wires

This is the scary part. Use your wire cutter, and snip off every wire but the Orange and Black. These are what you'll be splicing together. You're essentially powering your rear doors and tower with the same channel from your head unit.

You'll be splicing these wires together:

Left Speaker:
+ Brown --- Dark Blue w/ White
- Yellow --- Light Green w/ Black

Right Speaker
+ Dark Blue --- Dark Green
- Light Blue --- Light Blue w/ Black

This Diagram will help you if you don't trust me:

Image uploading. Refresh page to view

After splicing, snip off the orange (Amp Turn-on) and Black (Ground) and close them off. You No longer need these (Unless you want an aftermarket amp, these could be used for that (I think).

Image uploading. Refresh page to view

Step three: Put everything back together.

It's as simple as that, I'm sure someone here that knows more than my *Extremely Limited* knowledge of electrical, has a better solution, but this seems to work. SO have at it!

P.S. I'm not responsible for someone blowing up their van while following my instructions. :banana:

 

[BuddyHuggs]

Cool write up, those pics aren't showing up tho! I may use this

 

[chrstphr81620]

No Pics? Hmm... Showing up on my side. I'll try a new image host.

 

[MI_Ghost]

Being a How To. Upload them to the gallery or embed them into the post. Image servers are getting unreliable

 

[chrstphr81620]

On it!

 

[juststartin]

The're working now, great write up

 

[MI_Ghost]

Good info. Thanks for the write up.

 

[BuddyHuggs]

There they are! Thanks for sharing this info with us. Is the project any different for those with the rear heat?

 

[esc]

That is good info. I have an aftermarket head unit, I'll have to go see if my rear speakers work.

Instead of cutting up the factory plug, I may just use a crimp in wire splicer to make the connections.
For that matter...I wonder what would be needed to get the factory amp to work?

 

[chrstphr81620]

That is good info. I have an aftermarket head unit, I'll have to go see if my rear speakers work.

Instead of cutting up the factory plug, I may just use a crimp in wire splicer to make the connections.
For that matter...I wonder what would be needed to get the factory amp to work?

You could try to make it happen, but it would be overkill. Your aftermarket H.U. should already have an Amp in it to power the rears. What really needs to happen, is Metra needs to make an actual clip that you plug right into the wiring harness off the amp, but we can't be that lucky.

Truthfully, I'm not sure why the factory amp stops working after installing a stereo.. but if it's as simple as connecting a turn-on somewhere, it may be worth looking into. Not sure if the speakers may be damaged though with Two amps trying to power them.

 

[chrstphr81620]

There they are! Thanks for sharing this info with us. Is the project any different for those with the rear heat?

I can't imagine it is, you may have some stuff to work around to get to the amp though. I'm pretty sure the rear heat unit is posted up in front of the gas fill indent, so it shouldn't be in the way at all. You may have to move a heat duct to get to the amp, but I can't imagine that involves anything more than just lifting it out of the way.

 

[JohnMontana]

This is awesome. I didn't even realize the door speakers were not working properly. Mine are working but only low bass. I hope removing the amp helps. Thanks for putting this together.

 

[esc]

My rear door speakers are doing the same thing. They sound like really quiet sub-woofers.

 

[BuddyHuggs]

That's because the signal is split between the pillars and Dutch doors.

 

[esc]

The speakers on the sides in back sound fine. Loud and full range.
The back door speakers are VERY quiet and don't produce anything over about 100 hertz.
I wonder if this is what leaks through the amp when it has a high level input?
I do have a box that modulated high level inputs to produce a low level output that can be fed into an amp.
I may play around with trying to get the factory amp to work...

 

[chrstphr81620]

The speakers on the sides in back sound fine. Loud and full range.
The back door speakers are VERY quiet and don't produce anything over about 100 hertz.
I wonder if this is what leaks through the amp when it has a high level input?
I do have a box that modulated high level inputs to produce a low level output that can be fed into an amp.
I may play around with trying to get the factory amp to work...

You can give it a try, I guess if you already have the module it might work. But this is a free method, and after installing a new HU you don't need the amp anymore. :dance:

 

[esc]

I don't mean to detract from your walk though in any way. If it weren't for you bringing this up, I have no idea when or if I would have noticed my rear speakers were not working. In fact I may still do what you have done. But if there is a chance I can take two otherwise useless pieces of junk that i have laying around(factory amp and signal modulator) and turn it in to more power for the stereo I figure it's worth a try.

 

[chrstphr81620]

I don't mean to detract from your walk though in any way. If it weren't for you bringing this up, I have no idea when or if I would have noticed my rear speakers were not working. In fact I may still do what you have done. But if there is a chance I can take two otherwise useless pieces of junk that i have laying around(factory amp and signal modulator) and turn it in to more power for the stereo I figure it's worth a try.

I wasn't being defensive, sorry if it came off that way. I've got an aftermarket amp powering my sub currently, but I'm actually pretty impressed with the sound of the stock speakers powered by my new HU. And of course, as I mentioned before, I'm not in any way an expert in electrical or car audio. But I sure have learned a lot with this Van and friends vehicles. (You think our amp is a pain, try working on a Tundra)

 

[esc]

I'm sorry if i misunderstood.
You have provided some very useful and, in my case, timely information.

Thanks!

 

[gavio]

The rear door speakers are supposed to be subwoofers, they are referred to as such in the FSM.... WHen they are working the way the factory intended, they won't produce anything but low base.... I'm not saying it's the best way, but it's GM's way.... I never tried it, but I imagine if you ran a complete signal to them, they wouldn't sound very good in the upper ranges....