i plan on have 2 head unit install on my car...example: 1st radio is on doing its thing, when i turn on the 2nd radio...1st radio shuts off....? get a clue yet...?

if anyone knows please this would be very helpful for me.

 

why do you want to run 2 head units?

 

I'm guessing he wants to keep the factory unit working so its not a dead unit once he puts in the aftermarket one...

How do you plan on wiring your speakers up?


Well you would have to relay the secondary power to the factory deck, and use the remote wire on the aftermarket deck to as your trigger wire. I don't think this would be too much load for the remote wire, but check first. This should work, maybe someone else could chime in who has done this before?

 

reason why is because my 1st gen tsx stereo is equipped with the factory nav system. Problem is i cant have 2 radio driving output signals to my speakers...(BLOWS FUSE)...and another example is when the passenger dont know that im actually playing music out of the aftermarket headunit and goes and turns on or changes track on the factory radio (automatic turns factory radio on - BLOWS FUSE)...so i need to wire up a spdt relay so that the factory turns on when ignition starts, and by turning off factory radio, aftermarket HU turns on....

 

^^so with the help of the relay, if im using my aftermarket HU, by any chance someone turns on the factory HU, the aftermarket turns off...!

 

Depending on the model year of your car, this may not be possible.

What are you trying to accomplish? Maybe there's a better way of going about this?

 

still don't understand why are are trying to run 2 units. it will be ALOT easier to change your setup to one system that does everything you want. either way, it is hard to do this without tapping into the "off" signal from the factory HU. aside from shutting the factory unit on/off you will need to send the audio signals to the factory amp from the 2nd unit.

here's something i drew up that should work for the powering both units without too much complications. this setup will interupt the ACC power to the factory unit when the 2nd unit is on. you'll need to find the ACC wire from the back of the unit and the ground wire. cut the ACC wire and connect the unit side to 30. connect both the car side ACC and 2nd unit ACC wire to 87A. tap ground to 86. connect remote wire to 85. this will cut the power to the factory unit once the 2nd unit comes on. the only way to turn on the factory unit after that is to shut off the 2nd unit. that's the easy part. you still need to send signal to the factory amp.

find all the signal wires from the amp and send all speaker wires from the 2nd unit to the corresponding wires from the amp. to prevent any feedback i would tap into the amp wires with an in-line diode for each line. hope that helps.

but like i said before, the best/safest way to do this is to get one system that does everything you want.

 

Thanks for the advices guys...I just don't like the use of a ipod integration device....no sound controll, no eq freq adjustment....so with an alpine hu install I can use its amp plus my factory amp to power up these soundstream sst6x9 & sst5x9 speakers.

But as for powering up my factory amp....im going to make a t-harness and use either hu for the job....!

 

Why not use your factory HU as an aux source to the aftermarket HU?

I would not recommend having two amps connected to the same speakers (and therefore to each other) regardless of whether they are powered or not.

Does the HU you are planning to install have enough channels for all the speakers? Or will you get a crossover to send the front channel hi's to the tweeters in the dash and the lows the doors?

 

are you running two different sets of speakers? one for the factory unit and one for the 2nd HU?

why can't you control the eq off the HU with ipod integrations? most (if not all) adapters will still allow you to adjust bass/treble/fade/balance.

you cannot run two amps to the same set of speakers at the same time. it just doesn't work that way. with the setup you want, you will need to run the factory amp with both HU.

why not just run the Alpine unit alone? what's the benefit of keeping the factory unit???

 

the factory and ipod features of adjusting the bass/treble/fade/balance just doesnt cut it for me, i want to be able to adjust all of that and also the HPF (high pass filter) & LPF (low pass filter) so yeah only an aftermarket HU will be able to do that.

the alpine HU harness is connected with the factory HU harness....problem is when i installed my soundstream SSt6x9...the factory amp was not able to push the 6x9 at its full potential...now with the alpine hu radio amp and factory amp combined...the 6x9 are booming...just needed someone to teach me or show me how to connect a relay as described ^^^....!

i need the factory to work as well because without it, my nav voice wont work without it....!

 

Did you read post #6 and #9?

 

Hehe....what don't u get, it is already done with....i've been running this setup for a week or so...I just needed someone to tell me how to wire up a relay....!

On 04 tsx...we don't have xm where I could tap on the the speaker output to select aux on our factory hu...so this is the only way for now...don't need no $80+ ipod integration with aux output....on my alpine I get ipod connection....usb...cd with mp3 data....n cd audio...also I got a working cd changer...

 

your running power to your 6x9 from your factory amp and Alpine HU? I would advise against that if you are. you need to power it with one source to avoid any feedback.

sounds like you have all the audio signals figured out. if all you need is to interrupt the power then follow the wiring i have above.


imo, it would be best to select an aftermarket unit that has navigation capabilities and just bypass the factory setup all together.

 

yeah all my speakers are all power up by both factory and alpine head unit...the factory amp is only power on when "A REMOTE WIRE" is trigger on, like for example the factory hu or alpine hu....so remember like i said....im only using either one at a time........!