Hello,

I am installing a new radio to my G35 2003 sedan w/ Bose system

- Metra 99 - 7604
- PAC ROEMINS 2
- METRA 70-7550
- (wire diagram in Amazon pictures)

First I tried using the 70-7550, it came with no ground wire so I grounded stereo to chassis. Stereo only turned on when connecting all red and yellow wires but no sound.

Then I tried using the PAC ROEMINS 2, it came with black wire but it was not working so I connected black wires from PAC and Stereo to chassis. Stereo only turned on when connecting all red and yellow wires (4 in total) but no sound. I got sound when connecting the blue/white wire from PAC to all the red and yellow wires (5 in total).

I tried following Wrathernaut Guide diagram but did not work for me unfortunately.

Question now is:

Is it ok for all 5 wires (all red, yellow and blue/white) to be connected together? If not what can I do to make it work properly?

(DIsclaimer: I am not a car professional, simply enjoying this car project, if anyone is by NYC hit me up, I down to meet up in person)

 

A good place to start would be the Audio Section of the FSM for your vehicle

https://www.nicoclub.com/service-man...F2003%2Fav.pdf

See page AV- 5
BOSE SYSTEM
Refer to Owner's Manual for audio system operating instructions.
Power is supplied at all times

through 15A fuse [No. 37, located in the fuse and fusible link box]

to audio unit terminal 6, and

to Bose speaker amp. terminal 11.

through 15A fuse [No. 17, located in the fuse block (J/B)]

to woofer terminal 6.
With the ignition switch in the ACC or ON position, power is supplied

through 10A fuse [No. 6, located in the fuse block (J/B)]

to audio unit terminal 1
Ground is supplied through the case of the audio unit.
Ground is also supplied

to Bose speaker amp. terminal 24, and

to woofer terminal 5

through body ground B5 and B29.
Audio unit and A/C and audio controller are connected by FPC (Flexible Print Circuit).
A/C and audio controller integrates A/C switches and audio switches.
When A/C and audio controller is pushed to audio switch, it send audio signal to audio unit.
Then audio signals are supplied

through audio unit terminals 1, 2, 3, 4, 13, 14, 15, and 16

to Bose speaker amp. terminals 4, 5, 6, 7, 17, 18, 19, and 20.
Audio signals are amplified by the Bose speaker amp.
The amplified audio signals are supplied

through Bose speaker amp. terminals 1, 2, 8, 12, 13, 14, 15, 21, 25, and 26

to terminals 1 and 2 of front door speaker LH and RH

to terminals 1 and 2 of rear door speaker LH and RH

to terminals 1 and 2 of tweeter LH and RH.

to terminals 1 and 2 of woofer.
When one of steering wheel audio control switches is pushed to volume up, seek up, or mode ON, resistance
in steering switch circuit changes depending on which button is pushed. This will change voltage. Power is
supplied

from audio unit terminal 22

through combination switch (spiral cable) terminal 34 and 20

to steering wheel audio control switch.
Ground is supplied

from steering wheel audio control switch

through combination switch (spiral cable) terminal 17 and 31

to audio unit terminal 25.
When one of steering wheel audio control switches is pushed to volume down, seek down, or power ON,
resistance in steering switch circuit changes depending on which button is pushed. This will change voltage.
Power is supplied

from audio unit terminal 23

through combination switch (spiral cable) terminal 26 and 16

to steering wheel audio control switch.
Ground is supplied

from steering wheel audio control switch

through combination switch (spiral cable) terminal 17 and 31

to audio unit terminal 2

Good luck

 

Woah Super Admin, thanks for the link, will try to digest all the information since I am not too car savvy. If anyone else may have had similar issues or can add their .2 cents it would be appreciated as well.

 

The radio and amp are never going to turn off with all those wires connected together. The yellow is constant power, and is supplied to the radio whether the car is on or off, so that it can retain station memory and other settings. When you connect it to the red wire (power when car is on) you're telling the radio that the car is on, so it won't turn off. You're also sending power back through those yellow wires to anything else on the circuit and telling them the car is on, so you can screw up other things in the electrical system that aren't supposed to be powered on when the rest of the car isn't.

There are literal hundreds, and likely thousands who have connected things up according to the wiring chart and had it work great. Since you started with a 70-7550 instead of going directly with the recommended ROEM-NIS2, and say you're not a car audio guy, I'm going to make the assumption that you've wired it up incorrectly and should get assistance before going any further, because based on your other posts, your Bose amplifier is probably dying and hooking it up incorrectly could have killed it, or it's inconsistency is your problem. The amplifier generally outlive the radios, so replacing radio before amplifier is sound advice, but it looks like you're going to need to replace more than the radio.

The 2003 Sedan w/Bose uses a separate amplifier for the subwoofer, so keep that in mind when moving forward.

 

Thank you for your advice, seems like I will have a friend take a look for me. Amplifier wise, I ended up buying another one from ebay but still had radio issues, that is why I am changing the entire head unit. I will make sure we follow the wiring chart this time around. THANKS!