Aftermarket head unit wiring help

[doclees]

Hey folks, Replacing the OEM unit with a Kenmore(Haha Kenwood). The wiring harness adapter seemed to match up at first install. I got power but no sound. So I did the real bright thing of pulling all the connector pins from the adapter and thought it would be so simple to match the pins with position as seen in the Bentley manual. Not so. Can anyone jump in and reconcile the pin location numbers seen in the Bentley page with my page from my new unit?

[mslevin]

White: 1
White/Black: 8
Gray: 2
Gray/Black: 11
Green: 12
Green/Black: Not sure
Purple: 14
Purple/Black: Not sure
Red: 5
Yellow: 9
Black: 15
Brown: N/A I think
Blue/White: 16
Light Blue/Yellow: N/A unless you have a steering wheel adapter

Does that help at all?

[doclees]

Thanks. Its the unsure ones that have me going. I hate not knowing. I dug into the wiring diagram and it defines them more clearly. The number 6 pin is missed labeled in the pic. It should read right rear speaker. Now I can figure the proper + - lines.

[JDStrickland]

POINT OF ORDER
Your factory head unit is a pre-amp. The outputs of the head unit do not go to the speakers, they go to the amp. The head unit spits out High, Mid, and Low range, plus a ground for both the left and right channels. The amp divides this into the various speakers.

The pics that you posted have an error, notice that there are three pins with left front signals, bout only on pin with right rear signals.

I found that of all of the pins that go out of the head unit, only 8 are audio lines. I assumed hi, mid, and lo, plus ground for left and right, that makes 8 audio signals. Your pictures indicate that there is Left and right front and left and right rear, two audio lines for each so one must be the audio and the other the respective ground. This is plausible, and arguably a better explanation than the one I came up with. The downfall of the pictures you posted is that there is one too many Left Front lines, and one short on the Right Rear lines. The amp must divide the signals into hi, mid, and lo ranges, which is a bit different than the scheme that I came up with.

The point that I was leading up to is, you may find that when you replace the head unit, you might run into issues that are resolved by rewiring the speakers around the amplifier. The amplifier lives in the trunk, basically at the C Pillar. Remove the trunk liner from the left side of the trunk, the amp is visible basically directly below the hinge of the trunk lid.

[doclees]

Found the first problem. Pin numbering in the picture above does not match the BMW connector in my 325. Have power but no sound yet. I hate stuff that is supposed to be plug and play but ends up being a headache. Rather have the headache warning from the start.

[doclees]

POINT OF ORDER
Your factory head unit is a pre-amp. The outputs of the head unit do not go to the speakers, they go to the amp. The head unit spits out High, Mid, and Low range, plus a ground for both the left and right channels. The amp divides this into the various speakers.

The pics that you posted have an error, notice that there are three pins with left front signals, bout only on pin with right rear signals.

I found that of all of the pins that go out of the head unit, only 8 are audio lines. I assumed hi, mid, and lo, plus ground for left and right, that makes 8 audio signals. Your pictures indicate that there is Left and right front and left and right rear, two audio lines for each so one must be the audio and the other the respective ground. This is plausible, and arguably a better explanation than the one I came up with. The downfall of the pictures you posted is that there is one too many Left Front lines, and one short on the Right Rear lines. The amp must divide the signals into hi, mid, and lo ranges, which is a bit different than the scheme that I came up with.

The point that I was leading up to is, you may find that when you replace the head unit, you might run into issues that are resolved by rewiring the speakers around the amplifier. The amplifier lives in the trunk, basically at the C Pillar. Remove the trunk liner from the left side of the trunk, the amp is visible basically directly below the hinge of the trunk lid.

Thanks,yes
In figuring out that the pin positions were off I started to think that I was looking at the wrong wiring diagram and maybe there is an amp back there. Thought I remember seeing one when resetting the convertible top motor. Guess I will see if that is powering up.

[JDStrickland]

With what you guys have, and what I did many months ago to map my audio system, I have come up with the following pin outs on the head unit,

Pin 1 L Front + Yel/Red
Pin 2 R Front + Blu/Red
Pin 3 L Rear + Yel/Blk
Pin 6 R Rear + Blu/Blk
Pin 8 L Front - Brn/Org
Pin 11 R Front - Brn/Org
Pin 12 L Rear - Brn/Org
Pin 14 R Rear - Brn/Org

My idea of hi, mid, and lo, plus ground is no longer valid. Now the convention is Left and Right, Front and Rear, with a + and - for each. This makes more sense, by the way. You have 8 outputs from the head unit, that go to the amp, and 20 outputs from the amplifier that go to 10 speakers.

[TheDurk]

Thanks,yes
In figuring out that the pin positions were off I started to think that I was looking at the wrong wiring diagram and maybe there is an amp back there. Thought I remember seeing one when resetting the convertible top motor. Guess I will see if that is powering up.

'vert amp is not in the trunk. What you saw is probably the CD Disc Player, or its holder bracket. The amp is behind the rear seat on the passenger side. The best thing you can do is rip it out, and bridge the input and output speaker wires. I put my crossovers where the amp was and connected the input wires there and then used the exiting wires to power new component speakers in the doors. The amp is a piece of junk, and deserves no better fate than being put out of its miserable existence. Your new HU is guaranteed to perform better with it in a dumpster as opposed to being in the car.

[doclees]

Haha! Thanks Thedurk. Really this is the wife's car and I haven't had to do much to it for a few years. After I realized JDStrickland said trunk hinge I knew he was talking coupe. For the fun of it(sarcasticly said) I pulled all the trunk liners and CD player mounts to clean it up and have more trunk space. I will bridge the wires but why isn't the stock amp preventing power getting to speakers with new amp? Also it appears the antenna has a powered signal booster. Will/can/should this be powered by my new units antenna power line?

[TheDurk]

Haha! Thanks Thedurk. Really this is the wife's car and I haven't had to do much to it for a few years. After I realized JDStrickland said trunk hinge I knew he was talking coupe. For the fun of it(sarcasticly said) I pulled all the trunk liners and CD player mounts to clean it up and have more trunk space. I will bridge the wires but why isn't the stock amp preventing power getting to speakers with new amp? Also it appears the antenna has a powered signal booster. Will/can/should this be powered by my new units antenna power line?

I don't know the answer to either question. My antenna works fine--I connected blue/white to T16 on the harness but I don't know if it does anything. The stock system on mine was DOA at both HU and amp when I got it so I don't know about that either.

[doclees]

Well it is almost done. It does need the antenna signal booster powered. Had 0 stations without. Sounds much better but I have a speaker issue. When the rain stops I can give more info. Getting cracking in left door speakers and no sound from left foot well speaker. I have quadruple checked my bridge wiring and unit to adapter to BMW plug. Looks good. 2 questions. 1. If my foot foot well speaker is blown can it cause the door speaker cracking? 2. Can color blind people do this wiring.

[doclees]

Here is the update. Left foot well speaker just had wire fall off. She must have hit a hell of a bump. Door still crackles but having the other speaker back online dulls it. Door speaker will need to wait until warmer dryer weather. Brittle plastic you know.
I will post the wiring bridge for the amp bypass when I have it in a form people can read. Also to note the wiring loom from the new unit and the BMW adapter give you about another foot of wiring which makes getting the unit back in not happen easily. Plus this unit has a flat aluminum heatsink on the back. having that press up on wires makes me nervous so I'm going to shorten it up. Thanks for the help.