I'm giving Mom's Trailblazer a Partial Bosectomy

[Juicy K]

I have done it!!! Convinced my Mother that her wanting music in the truck, and a Bose system that does not work under 65 degrees is a dumb idea. (plus she likes the idea of streaming pandora)

Since She bought the truck in January of 2009 the stereo has only worked above 65ish degrees, I have gone through all of the connectors cleaned and reset them, found out the relay inside the amp is not the problem. This is the first vehicle she has owned with a "premium stereo" (Her and my Father seem to think Bose is the best there is) and she was hesitant to let me replace it because "Nothing will sound as good"... I finally got through to her that the stereo does not sound to good when it does not work...

She wanted to do this on the cheap so for now we are keeping the factory speakers.

Since the speakers have a 2ohm impedance, I was a little worried about over-driving a new head unit (and the fact head units only power 4 channels). I told her the only safe way we could power the speakers was with an external amp.

My Mother took it upon herself to look for a head unit (she ran them by me just to make sure it did what she wanted) we decided on the JVC K900BT, it is a double-din with bluetooth, 2 USB inputs, front 3.5mm AUX 3 sets of RCA out, and time alignment. All for $150

I knew I had to find an amp that would power all 6 speakers but it could not cost much, so I decided on the PPI Sedona 580.5.

I am going to wire it up in this fashion, through the output harness that was plugged into the Bose amp.
Front Channel = Dash Speakers
Rear Channel = Rear Doors
Sub Channel = Front Doors (wired into the same channel)

I know it will take some tuning of the crossovers and T/A to get it sounding decent.

I know this install is nothing special, but I will be taking photos during the install just to document it.

We have all of the big stuff (Head Unit, Amp, and Chime interface/harness) Just waiting for all the little stuff like RCA cables and ring terminals to come in.

She is just under $300 dollars for everything, so not too bad.

 

[Juicy K]

I got a chance to mess around with the Trailblazer today, I wanted to make sure I had the wiring right to output from the AMP to the speakers. While checking to see what the Final impedance (after wiring) was at the plug that goes to the speakers from the Bose amp I was surprised at what I found.

Left Dash : 4.4 Ohms
Right Dash: 4.4 Ohms
Left Front Door: 1.3 Ohms
Right Front Door: 1.3 Ohms
Left Rear Door: 2.7 Ohms
Right Rear Door: 2.6 Ohms

I will say this was checked with an ELCHEAPO Harbor Freight Multimeter so YMMV.

But most of what I have seen is at least the Front Doors are 2 Ohm at the speaker, so I am unsure as to the rather large difference here. Not a problem though, I will wire the front doors in Series and come out at 2.6 Ohms, and it will rise even more once the voice coils heat up, and it will fluctuate with frequency change.

Just figured I would post this little update. We are still waiting on both sets of RCA cables, Dash Kit, and circuit breaker.

Quick question, off the top of your head. Does the LUX amp have a turn on lead, or is that controlled by the Class 2 data cable?

 

[IllogicTC]

Power is switched on via data bus signal.

It has a +B lead that is hot at all times, various input/output wires along with some drain wires, a ground of course, a couple wires to the noise-reduction system, and then class 2 serial data wire. No remote.

 

[Juicy K]

Power is switched on via data bus signal.

It has a +B lead that is hot at all times, various input/output wires along with some drain wires, a ground of course, a couple wires to the noise-reduction system, and then class 2 serial data wire. No remote.

Thanks for the verification. I have been digging through the 02" wire schematics and the only thing I could find that I figured would turn it on was "info" from the Class 2.

Ill just run a remote from the new H/U.

 

[Juicy K]

Somehow got most of Mom's Bosectomy done last night. We decided to extend the Bose harness so we did not have a large cluster of wires running under the rear carpet. So that will be finished tonight, then hook up the power wire, and I can start tuning.

On another note... I wish the Bravada stereo was as easy as the Trailblazer's to remove. It was nice not having to mess with the center console just to get to the stereo.

 

[Juicy K]

Just figured I would put this here.

For the 2002 Trailblazer with "LUX" Bose, the output to the speakers from the amp is such. (Impedance was taken at the plug that goes into the Bose amp)

I decided I would post this since it seems most of the wiring schematics posted on this subject are for "NON LUX", I downloaded the 02' Schematics, and then verified the wires went to the correct speakers by hooking up a 9Volt battery to each set of leads.

Left Front Dash: Dark Blue + pin A4 / Light Blue - pin A6 4.4 Ohms
Right Front Dash: Dark Green + pin A8 / Orange - pin A9 4.4 Ohms

Left Front Door: Tan + pin D / Grey - pin E 1.3 Ohms
Right Front Door: Light Green + pin F / Dark Green - pin C 1.3 Ohms

Left Rear Door: Brown + pin A2 / Yellow - pin A3 2.70 Ohms
Right Rear Door: Dark Blue + pin A11 / Light Blue - pin A10 2.6 Ohms



Since I am running a 5 Channel amp, I am running the Front Doors off of the Subwoofer channel. The amp is only good down to 2 Ohms on the "Sub" channel so I have wired the front doors in Series to give me an estimated impedance of 2.6 Ohms (I am sure it will be a little more considering the run of wire will be going from the back and forth twice)

 

[IllogicTC]

Just figured I would put this here.

For the 2002 Trailblazer with "LUX" Bose, the output to the speakers from the amp is such. (Impedance was taken at the plug that goes into the Bose amp)

I decided I would post this since it seems most of the wiring schematics posted on this subject are for "NON LUX", I downloaded the 02' Schematics, and then verified the wires went to the correct speakers by hooking up a 9Volt battery to each set of leads.

Left Front Dash: Dark Blue + pin A4 / Light Blue - pin A6 4.4 Ohms
Right Front Dash: Dark Green + pin A8 / Orange - pin A9 4.4 Ohms

Left Front Door: Tan + pin D / Grey - pin E 1.3 Ohms
Right Front Door: Light Green + pin F / Dark Green - pin C 1.3 Ohms

Left Rear Door: Brown + pin A2 / Yellow - pin A3 2.70 Ohms
Right Rear Door: Dark Blue + pin A11 / Light Blue - pin A10 2.6 Ohms



Since I am running a 5 Channel amp, I am running the Front Doors off of the Subwoofer channel. The amp is only good down to 2 Ohms on the "Sub" channel so I have wired the front doors in Series to give me an estimated impedance of 2.6 Ohms (I am sure it will be a little more considering the run of wire will be going from the back and forth twice)

The problem with the sub channel is it'll hold back on the full range of what the front woofers are capable of, and may go below the range they're good at of course. That, and might very well get blown since you're rigging up a different amp.

However I do appreciate that you're willing to do all this and (try to at least) make it work, if you succeed this info is valuable, and if everything goes horribly wrong it's still valuable.

And what gauge is the factory wiring for the speakers, anyway? 14? 14-gauge copper has a resistance of .002525 ohms per foot, so unless it's a decent run it's not going to really increase it by much Total run back and forth for both in series is maybe 25 feet of wire? Maybe I'm giving them too much credit on gauges though, probably stuck with 18 or something (.006385 ohms/ft).

 

[Juicy K]

The problem with the sub channel is it'll hold back on the full range of what the front woofers are capable of, and may go below the range they're good at of course. That, and might very well get blown since you're rigging up a different amp.

However I do appreciate that you're willing to do all this and (try to at least) make it work, if you succeed this info is valuable, and if everything goes horribly wrong it's still valuable.

And what gauge is the factory wiring for the speakers, anyway? 14? 14-gauge copper has a resistance of .002525 ohms per foot, so unless it's a decent run it's not going to really increase it by much Total run back and forth for both in series is maybe 25 feet of wire? Maybe I'm giving them too much credit on gauges though, probably stuck with 18 or something (.006385 ohms/ft).

I was a little cold (installing outside), but I believe the front doors are 14 or 16 gauge, the rest look to be 18 gauge, I did not pay too much attention.
We will eventually replace the speakers, and she understands there is a chance the speakers will turn to toast.

I plan on crossing over the Front Doors as high as the amp will allow "450Hz", the Dash I feel I could cross over pretty low considering their size, and I will most likely Bandpass the Rear Doors between the Dash and Front Doors,then work from there, and hope I can pull it all together with Time Alignment. Wont be optimal, but I am sure it will be better than no music.
As long as we dont get any clipping I am almost sure the speakers will live a little bit. I personally overpower all of my speakers and have yet had any problems (unless the problem is forced ) . It also helps she tends to be conservative with the volume knob.

 

[Juicy K]

I hooked up the amp temporarily yesterday so I could get a base tune for the crossovers on the amp.

I am full on impressed with my Moms setup, it produces more detail than the Bose amp and H/U ever could think of, it plays with authority gets louder than she would ever want it and it still stays clean.

I did notice a little distortion from the Passenger Dash speaker on certain songs, but again that was at higher levels than she will ever listen to.

I am going to have to break up the wire harness so it is not a huge bundle of wires running under the carpet to the Bose output harness (cannot properly fit the passenger side lower interior trim).

When we get the remaining RCA cable (waiting on a slow EBAY seller), I will take photos of everything and post them since I will have to tear back into it. But I think I will wait until we are back into 40+ temps.

 

[Juicy K]

Got everything finished today (except cleaning up the old Bose output wiring harness), and have to clean up wiring in the storage compartment in the floor), spent a little bit of time tuning it. I still cannot believe how this turned out. Now my brother wants me to do the same in his Envoy.

I think I will make a small rack for the amp and we need to find out where she wants the mic mounted so it will be on the visor for now.