I'm a new Crossfire owner (just bought an '04, and am loving it), but one of the first things I wanted to do was fix up the stereo. So, I read a bunch of the threads here, and it seems like everyone believes the stock AMP is just a two channel unit. After I looked at the wiring (it's great that the service manuals are available here!), my thought was that the AMP had to be a 4 channel AMP, that they wired the front and rear channels together because the stock head unit was only two channels (no one I know designs an AMP w/ 2 inputs and 4 outputs...)

Anyhow, I tested my theory by going in and clipping the wires going to pins 6 and 7 on the AMP. Sure enough, the door speakers on the right went out, but the sub still worked. So here's the pin out I determined:

EDIT -----
AMP pin 6 - (was Right Door speaker input (+) ) should be Right Door speaker input (-)
AMP pin 7 - (was Right Door speaker input (-) ) should be Right Door speaker input (+)
EDIT-----

AMP pin 10 - Right Sub input (+)
AMP pin 9 - Right Sub input (-)
AMP pin 1 - Left Door input (+)
AMP pin 2 - Left Door input (-)
AMP pin 8 - Left Sub input (+)
AMP pin 3 - Left Sub input (-)

I installed a new head unit (a Pioneer DEH-P6100BT, highly recommended by the way). I used the existing wires to drive the Subwoofers from the sub preamp outputs, and ran two new pairs of wires between the door wires I clipped at the amp (pins 6/7 and 1/2) and the front speaker preamp outputs. Works like a champ, and you can individually adjust the volumes of the subs vs. the door speakers using the fader.

As a side benefit, if you do this, you can use the adjustable crossover functions in the head unit (almost all of them have them) to avoid having to put the capacitors in the doors. I set mine to limit the subs to < 125 Hz, and the front speakers to > 100 Hz. I'm very happy with the results.

 

So what exactly did you do? You clipped 6/7 and 1/2 between the radio and the amp and then wired new wires to the door?

Wouldn't it be better to cut 8/18 and 7/17 on the output side and splice in from your head unit there? I would let the built-in amp handle the subs and the head unit handle the front door speakers.

See diagram attached.

 

Hey Spark.
Where did you find the Service Manual?
It's not available in the regular spot.

We all thank you!

 

As far as the service manual - I found it through one of the links in this forum, I don't remember which one. I know there are a few different links out there. Do a search on "service manual", and you should be able to find one that works. If you still can't find it, send me an email directly and I'll send it to you.

What I actually did was snip the wires on the amp input pins about 3" from the amp, then ran wires from there to my head unit pre-amp outputs. Picture below shows this. Note the two pairs (one yellow, one blue) of wires sticking up on the right. I just left these hanging, as they're the ones that go back to the splice (which I was too lazy to try & go find) and from there to the original head unit. The wires coming out of the amp, though, I connected to some old speaker wire I had laying around (one brown pair and one white pair) with crimp connectors, wound the wires around the cable bundle and routed them back to the head unit preamp outputs, which (in my case) were separate RCA jacks.



I suppose I could have wired around the AMP to the outputs, but one of my goals was to fully retain the speed sensitive volume adjustments that the AMP does. Wiring to the input side lets the amp adjust all of the speakers. I did not have to touch any of the wires going to the speakers themselves.

 

it sounds like your going to be a very nice person to have around the forums! Welcome and thanks for the info

 

Glad to help. I've found a bunch of useful stuff in the forums already, and am glad to do what I can.

 

Thanks for the insight. You present a good idea for how to separate the front and rear channels in the factory amp and use the built-in cross-over to deal with the front speakers.

But your labeling of the polarity of pins 6 and 7 is incorrect.

Wiring it the way you have would result in phase problems affecting the soundstage imaging, Thought the speaker would still work, it would sound better corrected.

Your labeling is inconsistent with the he factory wiring diagram. The application of a little logic shows that as well. Here is the correct polarity for each amp input side pin.

Note in your list you have

AMP pin 6 - Right Door speaker input (+)
AMP pin 9 - Right Sub input (-)

Logic: But these two pins are jumpered on the input side so it doesn't make sense they'd be different polarities. They should be

AMP pin 6 - Right Door speaker input (-)
AMP pin 9 - Right Sub input (-)


Correspondingly you have

AMP pin 7 - Right Door speaker input (-)
AMP pin 10 - Right Sub input (+)

But again these two pins are jumpered so the correct polarity would be

AMP pin 7 - Right Door speaker input (+)
AMP pin 10 - Right Sub input (+)



Your corrected pin-out would look like this


AMP pin 6 - Right Door speaker input (-)
AMP pin 7 - Right Door speaker input (+)
AMP pin 10 - Right Sub input (+)
AMP pin 9 - Right Sub input (-)
AMP pin 1 - Left Door input (+)
AMP pin 2 - Left Door input (-)
AMP pin 8 - Left Sub input (+)
AMP pin 3 - Left Sub input (-)

Here is a drawing showing the pin outs with labeling.


It's your car and wiring but I find that using the standard colors and wire made for the purpose pays dividends later when you go back and look at the install, or for subsequent owners who want to understand what's in there. It's a good idea to tape off and label any wires left unattached.

 

PPro -

You're absolutely right about the pinouts. That's a typo on my part (I didn't actually wire it like that). Good catch! You're also right that it would, as a minimum, screw up the phasing, and in the worst case, it might not work at all. On my Pioneer head unit, the pre-amp outputs are RCA jacks, and so I assume they're single ended, not balanced. If the AMP is really single ended (in spite of the fact it's labeled w/ (+) and (-) ), I'd probably not get any sound at all with the polarity backwards (and my head unit probably wouldn't appreciate driving the output into a short to ground).

I would have loved to use color coded wires, but that's not something I had laying around in my garage. I was proud I actually found two different colors of zip cord so I could keep the right and left straight. I did actually tape off the unused wires, and for good measure I put a copy of my marked up wiring diagram in the glove box for future reference. Thanks for the catch, and I'll try to go back & fix it if I can.

 

I'll bet you are. I still like the capacitor mod, because it works for those of us using the stock head (can't do without the British lady's voice in the NAV system! )

I never looked at the amp wiring until now - haven't even seen it in the service manual, but then, didn't ever go looking for it, either. Having you around will be a plus for the community here.

 

Great thread, just discovered it. Spark’s solution solves the exact problem I’m facing.

Now I want to buy a new HU (3 sets of pre-amp outs), and I want to give the installer the exactly correct instructions, leaving nothing to chance or interpretation.

Spark, could you or one of the other gurus here correct me where I got it wrong?

Instructions for installer
1. At the amp: about 2-3 inches from the amp, cut the wires at pins 6 & 7, and at pins 1 & 2. (Cut on the amp side of the existing wire splice as installed stock)
2. Splice new speaker wire at each cut, and run the new speaker wires up to the (new) HU
3. At the HU: connect the new speaker wires to the RCA jacks for “Front” pre-amp output
4. At the HU: connect the existing speaker wires (pins 9 & 10, and pins 8 & 3) to the RCA jacks for “Subwoofer” pre-amp output.
5. At the HU: ignore the pre-amp outs for “Rear” output

That look right? Anything here that will confuse a Best Buy installer?

Not having *any* experience at this, an ignorant question: how do the wires from a given pair of pins at the amp, become a single RCA plug on the other end? For example, the wires from pins 8 & 3 need to terminate at the HU in a single RCA plug that jacks into “Left Subwoofer” pre-amp out. How does 2 become 1?

 

Not to highjack thead, Is it possible to add input jack directly to amp for Ipod, then muting headunit?

 

No. The iPod output is not high enough to drive the amp. The amp receives a 12 volt signal from the head unit. The iPod output is only 0.2 volts.

 

Friends,

I just finished installing a older Pioneer Premier DEHP840MP. This was one of the first high end MP3 CD players made. It is silver with a dual fold down face plate and I must say it looks awesome in the console. The silver is perfect match. If I had to do this install again I would make one change to the above instructions.

Instead of cutting pins 6,7,1 and 2, I would cut pins 10,9,8 and 3. The reason is the harness adapter has wires in the proper location for the front speakers. Since the wires are already there in the proper location for the front speakers, they should be used for the front speakers. Then you can use your new wire then to drive the subs instead of the front channels.

Hindsight is 20/20.

Now for a question. My Pioneer has an "Illumination" lead. There was no matching lead on the car harness side. Does anyone know the best location to connect this illumination lead? It is just disconnected for now.

Regards,
John

PS. the RCA Preamp leads of this pioneer head unit drove the amp just fine and there no extra noise anywhere.

PPS. Wingman yous summary is correct, just switch the cut wires like I say for a more proper install.

 

Hi, I'm new to posting on the forum (though I've been reading for a while).

Sorry to re-open an old thread, but it seemed the best place. I've followed the advice here in preparation for adding an Alpine CDA-9886M head unit into my XF - very grateful for this info as I much prefer to use pre-outs.

I've planned everything out and made a wiring diagram. I'd welcome comments and if it helps someone else that's great.


The one question I have remaining is about powering-on the amp. Most head units have this capability. Does anyone know if the factory unit does this or is it a separate circuit?


Nice idea - I've used this approach. Another benefit, if you ever want to add an extra sub it would mean no extra cutting at the amp, just splice in again at the same join.

 

I also looked at the wiring at the AMP.
It has the wires 7/10 6/9 1/8 2/3 going separately into the wiretree, then at the stock radio we see just the 3 4 5 6 wires coming out.

It does not seem they are joined anywhere near the AMP.

So somewhere they are joined, behind the console? Anyone knows this?

 

This mod really makes the new head unit come to life!

If you are putting in a new head unit, this IS the best quick mod to get full sound from your new unit.

 

It definately allows for better settings if your unit has built in crossover etc. One thing to look out for is overall volume though. My head unit doesn't send out as much juice from the pre outs as the stock unit so maximum volume is much lower. This is not that big of a deal as at full volume there is no/minimal distortion but sometime I wish I could get it just a bit louder. SQ is way up though, being able to clip the bass down on the door speakers makes a world of difference. Also reduces all that rattle from the door handle and speaker surrounds for the most part.

 

The factory amp should not even work half way with pre-outs. You should only use speaker outputs to power the factory amp, just as the factory head unit does.

Cheers!

 

Mine is hooked up as described by the OP
HU front preout to L/R input on amp
HU sub preout to L/R sub inputs on amp

Only difference is his pioneer pumps more voltage out of the preamp than my alpine if I am not mistaken. I hooked it up like factory before I switched to preouts and volume was way higher but clarity at high volumes was garbage like stock as the speakers just can't handle it. Also couldn't control fronts/subs independently.

How did you do your setup? Just bypassed the factory harness straight to the amp using the regular L/R front wires coming out of the HU?

 

Just used this info to wire my HU to power all 4 channels separately. Works great! Now I can fade to the rear and boost the bass coming out of the rear speakers while using the HU's crossovers to eliminate most of the bass going to the front speakers. Sounds much much better now. The subs actually sound like they are doing something for the music in the car instead of just going along for the ride.
Thanks for posting up this info!