: Will this work / Aftermarket install

05-23-05, 03:51 PM
This will be a little drawn out, and probably boring, but please read the entire thing, as I need some advice. I am going to install an Alpine head unit in my '02 Seville SLS, and need to know if I am on the right track. I have searched for a simple way to do this, and thier are no easy ways. Here is what I know as fact:
By removing the factory head unit, I lose all of the chimes (door, low fuel, back up sensor, etc)
I lose OnStar (which is no problem for me)
I lose steering wheel controls
There are no aftermarket wiring harnesses that address these issues that are for a 32 pin connector, only the 24 pin connector.

What I plan on doing, is purchase male and female 32 pin connectors, extending the existing harness, and mount the factory head unit in the trunk. This will have all of my functions intact, with the head unit, out of the way. Then I will install the Alpine head unit, using all new wiring, with the exception of the speaker wires. I will cut them, so the stock head unit, will not be audible (The stock head unit will always be off). This should get my Alpine unit in perfect working order (with the exception of the factory subwoofer, and the center dash speaker (I assume)). The chime function only works through the front left speaker. To remedy this, I plan to wire from the stock head unit, to the center dash speaker, which I am going to assume, will not work after the new head unit is hooked-up. Does this particuler speaker have it's own channel, or is it wired in with something else? By doing this, the new HU will be functional, and the chimes, will work perfectlry, as the stock system, will think it is still okay. The Alpine HU has RCA connectors for an aftermarket amp. So I plan on buying one, and using it to power the factory subwoofer. What wattage is the factory sub rated at? Also, I will get the SWI unit, to remedy the steering wheel controls. The only thing I will end up losing, is the 10 minute power delay, which allows you to retain power, when the key is off. No biggy for me, as I never take advantage of this feature.

So here are a few questions.

1. Will the head unit in the trunk, and using only the factory speaker wiring, for the new HU, work? I am going to run new power feeds.

2. Does the center dash speaker have it's own channel, or does it run off of the same channel as another speaker (front, rear, sub)?

3. Will rewiring the front left speaker wiring, from the factory HU, which will always be off, to the center dash speaker, make my chime feature work perfect?

4. What wattage is the factory sub rated at?

I am a novice at this stuff, but this seems like it would work fine. If this will not work, please explain whyit won't work. Thanks for any advise that anyone can provide. I really need help on this one.


05-23-05, 07:56 PM

there is both of the 32 pin harness' mine are on the way.

05-24-05, 12:54 AM

there is both of the 32 pin harness' mine are on the way.

:yup: Pass it along, I like it :)

05-24-05, 04:13 PM
I have an idea for your stock head unit dude ....

Why not do as you planned , but mount the stock head unit so its acessable to the rear seat passengers ?maybe it can be mounted into the rear armrest ?
wire the rear speaker outputs from the stocker into a jack system so headphones can be used and the rear passengers can listen to music of there own choice ...and send your front speaker outputs to where they were supposed to go in your plans....

just an idea ive had for awhile...

Im no stereo installer tho ..but i always thought this could be done after seeing the Malibu Maxx

05-30-05, 09:15 PM
Hey i think i might be able to give shed some light.I have a 95 eldo & what i had to do to install my after market radio & keep all my goodies was to purchase the after market plug & install it to my factory amp which was located in my trunk,I then bought a solid wire which contains 9 color coded wires in it,(you can purchase everything at a audio shop)& ran the wires all the way to the front.ITs a timely process if the wires are ran together w/the factory ones.You will have to remove a few things.But at the end you will have the option of putting your factory radio back on if you sell your car without having to cut any wires.
I hope i could be of some help.

05-30-05, 11:01 PM
So the wire harness you bought connected at the amp, not the head unit harness? What happened to the stock head unit harness? Was it left open? The reason I am asking, is I thought that the aftermarket harnesses attatched at the head unit harness. I am beginning to think that they are supposed to connect at the amp. My head unit has a 32 pin connector. Every aftermarket set-up I have seen, has a 24 and a 12 or 14 pin connector. After checking around behind the rear seat, I found the amp. It has a 24 and a 12 or 14 pin. This is majorly confusing. It appeared that the smaller of the two connectors controlled the rear door speakers only. The larger of the two controlled the two fron t door speakers, door chimes, and subwoofer, amongst other things. Can you reply to this, as I am still confused. Thanks


05-31-05, 04:41 PM

Wow, I have to say your idea (first posting) is actually really good in theory - I can't believe no one else has posted this idea that I've seen (specifically reutilizing the center channel speaker for the chime, so no special adaptor is needed). FWIW, the front center speaker is a summed stereo (l+r mix thus effectively mono) signal, this process is performed internally by the amp module, and I would suspect the sub works much the same way.

Anyway, the center channel is worthless - this is a home theater concept (for the dialog in a movie) and not really needed in system geared for music listening IMHO. Besides, it is such a small driver that it is really just a narrow midrange, and probably picks up the slack where the front woofers drop off and before the tweeters pick up the upper midrange.

Basically, Ditch the factory speakers in front and get a good component system (woofer & tweeter) that will cover the full frequency range without the need for Delco/Bose's crappy squaker in the dash.

Now, as to the wiring, as you have stated (correctly) the harness issue is _almost_ a show stopper. You may need to cut if proper adaptors are not readily available, which is a poor solution to a bad problem, at least to the extent that it makes reinstalling the factory head more difficult down the road. Then again, if you do it right using insulated quick connects and hack the harnesses in an organized manner, and save the ends you cut off you could always put the factory harnesses back together with just a few plug-swaps and be good to go.

I think relocating the factory head to the trunk so that it will remain on the vehicle's class II comm buss is the best bet, this gets it out of the way and you never have to worry about it again. It will still pass the chime signals through to the center speaker (rewired to run off the front left outputs) and unless it gets turned on by mistake, the radio will never be audible as you pointed out.

You are also on the right track for the steering wheel controls - the SWI adaptor will take care of this rather easily. The only hang up is the sub - I'm not exactly sure how this is setup as my car didn't have the Bo$e system - which was a BIG plus for changing out to aftermarket, I did an Alpine head unit also BTW.

The problem with the sub is that the bo$e amps are internal (well, built on) to each speaker, and the input levels are not neccessarily standard pre or line level from what I understand. Thus, the preouts on the Alpine may overdrive the input on the sub casuing distortion and generally lousy sound. Most Alpines now have 4v preouts.

Further, the factory sub is not a great unit (nor are any of the factory speakers for that matter) and reusing them is a bit troublesome due to the slapped-on amp, and the not so great sound quality they are capable of.

All in all, I think you were on the right track with your first idea, except for the sub (maybe) and how to handle the wiring. If mating adaptor harnesses are availble, then this latter problem is solved straight out. If not, it'll just mean some splicing; which when done cleanly isn't really so bad.

Best of luck, I hope to see a post here that you got this done successfully.


05-31-05, 05:15 PM

Thanks for the post. My train of thought has changed a little though. A friend at work, has a brother and a friend, who are system installers. There is a module out, GMRC-03 or something like that, that is supposed to fit the new Caddy's. It eliminates the stock head unit, and has it's own speaker, for the chime function. It is on order, and I will see what it is about, when it comes in. As far as the stock sub, I plan on keeping it, at least for the meantime. the Alpine unit has RCA jacks for an aftermarket amp, and I plan on getting one, and hooking the stock sub to it. I do not know how this will work out, but I am going to try it. if it sounds like crap, I will change to a better unit.

It appears that the aftermarket harnesses are stock amp bypasses. The thing that is confusing to me, at least right now, is what happens to the stock harness, that was hooked to the factory head unit. The new harnesses look to attatch to the stock harnesses at the amp, with some new wiring for the new head unit. So the stock harness, that runs up into the dash, seems like it is not needed anymore. If anyone can confirm this as fact, please advise. If this is incorrect, let me know what happens with the factory harness.

I was thinking of changing out the four door speakers, to components. I am unsure if I will do this though. If anyone can point me in the direction of some decent speakers (read not over $125.00 per pair) I would appreciate it.

One last thing. Does anyone know the max watt rating of the factory subs? It is not listed on the sub magnet. I have the non-Bose system in my car. thanks


06-01-05, 12:13 PM

If this new module you're refering to works out, that'd be outstanding, as it would save a lot of work to rig up the retention of the chime. I would still be concerned about eliminating the stock HU as it will probably pop codes, but this isn't really such a big deal, they'll just show up in diagnostics mode (I guess that would just kind of bother me personally, to see the codes in there).

The question is, if this module does what you think it does, where does it get installed. My thinking is it should be up front so you can actually hear it, not in the trunk. Thus, maybe it plugs into the stock HU harness and the other end of this harness remains plugged into the tuner/amp module. This would seem to make more sense to me.

Back to the sub - since you don't have bose in your car, that is a good thing. At least you don't have to extract the built on amp and risk damaging the speaker. As to the rated wattage, I would guess no more than 30 watts RMS based on the capabilities of the factory amp. Remember, that one little module has to power 7 or 8 speakers (with sub and front center channel installed) and for it's physical size and the available input power, I can't imagine it running more than 25-30 watts to the sub.

Of course, these days power specs are ridicuosly overstated using "alternative" rating scales rather than RMS, the true measure of audio power. So, you'll see claims of 300-500 watts audio output power on factory systems, which these systems could never dream of actually touching on their best day. In any case, I'd say a smallish 50w amp to drive the factory sub should be more than enough.


06-01-05, 04:33 PM
Kevin, once again, thanks for the input. But a question for you. Where does someone, namely me, buy a 50 watt amp? The smallest I have seen is like 200 watts.


Southern DubVille
06-01-05, 10:24 PM
You might have to do a little digging for an amp at that rating but it shouldnt be that difficult, I've owned quite a few small amps Rockford Fosgate, Alpine, and Jensen, as they are a great source of clean power to feed my tweeters. Personally I preferred the Alpine above the rest, the 3522 or 3522s to be specific, now these two amps are no longer in production but if you are lucky you could look on ebay and they pop up every now and then. Alpine currently carries an amp that is rated:

50 watts RMS x 2 at 4 ohms
70 watts RMS x 2 at 2 ohms
140 watts RMS x 1 bridged output at 4 ohms
Stereo or bridged mono output
4-ohm stable in bridged mode
MOSFET power supply
Tri-Way capable
High-pass/low-pass (80 Hz) crossovers, 18 dB/octave
Variable 0-12 dB bass boost at 50 Hz
20 Hz subsonic filter
Speaker-level inputs
Gold-plated power and speaker screw terminals
this amp is like 100 bucks here is the link to it http://www.hookedontronics.com/show_product_details.jsp?cid=3594&c=0506Froogle&b=Alpine_MRP-T220
good luck and I hope this helps!


06-02-05, 05:06 PM
Here's a quick update. I received the GMRC-03 today. It stated that it was for cars without On Star, and without factory amp. My car has both. It also stated that I could use it, but I would have to bypass the factory amp, and not use the supplied speaker hook-ups. So basically, it was an aftermarket chime, as I would have to run all new wiring. I am returning it, and I have ordered a GMOS-06 interface. It supposedly is a plug and play unit. It retains the On Star (no big deal with me), the factory chime function and front left speaker location, and the factory amp can still be used. I guess I should have this piece by the beginning of next week, and after i get it, I will update with the results. I am assuming that by retaining the factory amp function, the factory subwoofer, will still be operational. Once I get everything installed, I will get pics up, with a report of how it is working.


06-07-05, 10:58 PM
Well the head unit is in. She's a real beut Clarke. I posted the update in a new thread. Check it out. It was rather simple to do.