Is it possible to add an aftermarket head unit and keep the stock navigation unit working?
I have an 04 accord and obviously it has navi and i am wanting to install a very nice sounding system. I don't care about the voice turn by turn option I always turn it off anyways, just too annoying. Stereo shops are telling me it can't be done but I don't understand why? can't I install the head unit with direct power and scab off the remote wire from stock harness to new HU? I don't see the problem since I can run all new wires to the speakers from the amps?? please Help

Thanks

Rich

 

you just install the aftermarket head unit in the pocket below the factory radio. the factory radio remains for climate control and other functions. then you can use the aftermarket head unit to power speakers, amps, subs, etc. and get any other ipod, sat, bluetooth, etc. features you want.

since the factory screen and radio remain, they can still function, just without sound. if you want the option for factory radio sound, just use a line output converter on the front to channel outputs and feed an aux in on the aftermarket radio. then you can use the in-dash changer, and other features. you'll just need to set the factory radio volume at a fixed level and only adjust volume on the aftermarket head unit.

 

Hope,
Are you saying that I can not only use an aftermarket head unit and still maintain my navi but I can also use my six disc changer with the aftermarket system?? If so can you be more specific on the details and the how to's

Thanks in advance,

Richard

 

i can draw a diagram later this evening for you.

 

That would be great thank you.

Rich

 

Here is an image to describe what I posted above.

Behind the head unit, cut the wires leading to the front speakers (left and right).
Splice in a LOC to reduce the factory signal to RCA's
Plug RCA's into the AUX input on your new head unit.
Set the factory radio volume at a fixed level that results in a signal at or just below the aftermarket head unit volume. Do this with the same CD in each.

 

2004 Honda Accord (6 Speaker System) Car Stereo Radio Wiring Diagram
Car Radio Constant 12v+ Wire: White/Green
Car Radio Switched 12v+ Wire: Yellow/Red
Car Radio Ground Wire: Black
Car Radio Illumination Wire: Red/Black
Car Stereo Dimmer Wire: Red
Car Stereo Antenna Trigger: N/A
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Front Speakers Size: N/A
Front Speakers Location: N/A
Left Front Speaker Positive Wire (+): Green/Black
Left Front Speaker Negative Wire (-): Light Green
Right Front Speaker Positive Wire (+): Green/Yellow
Right Front Speaker Negative Wire (-): Gray/Red
Rear Speakers Size: N/A
Rear Speakers Location: N/A
Left Rear Speaker Positive Wire (+): Blue/White
Left Rear Speaker Negative Wire (-): Blue/Black
Right Rear Speaker Positive Wire (+): Pink
Right Rear Speaker Negative Wire (-): Blue/Yellow

 

hope thanks for the guide. but what will this allow me to do? I think i'm ok with the first part of your instructions, but the last sentence made no sense to me. And if i cut the wires going to the front speakers from the stock head unit what does that do from me since I would be running new wiring from the amps. sorry i'm not quite understanding this, I just want to understand completely of what im doing before go and start something I can't finish.

Thanks,

Richard

 

no problem, thanks for asking detailed questions.

"Set the factory radio volume at a fixed level that results in a signal at or just below the aftermarket head unit volume. Do this with the same CD in each."

when you add an aftermarket head unit, that will be your volume control. you won't use the factory radio volume control at all. as a result, you want to set your factory volume at a fixed level (and leave it there). you determine what that fixed volume should be by comparing the factory radio volume (through the aux input on the aftermarket head unit) to the volume of a CD in the aftermarket head unit. this isn't crucial to understand until you have everything installed (kind of a last step).

when you install new amps and new speakers, it is a good idea to run new speaker wire. if you don't, you can tap the factory speaker wires behind the head unit. Doing this will require you either cut the factory wiring or buy two harnesses - Metra 70-1721 and 71-1721 so you can intercept wiring without cutting factory wiring. The harnesses are <$20 and would make connections much easier to make since factory wiring is so short.

i'll see what i can do for a much more detailed wiring diagram, paint can't give me enough detail so i'll use CAD.

 

Thanks that would be great! Man I wish you were in California you would definetly have my money! I have read alot of your sticky's and plan to put them to use....eventually

Thanks again

Richard