I know i have posted a lot of threads about head units and whatever but i'm so close to having everything working.


I have:

Alpine CDA 9856
Metra-70-1787




The 4 RCAs are correctly placed into the back of my head unit. The other part of it connects with wires from the wires coming out of the back of the alpine. Those wires deal with power, the RCAs deal with the speakers. One of the regular speaker wires coming out of the metra harness is blue with a white stripe, it says that it is the amp turn on wire.

At first i did not have that wire connected to anything, the radio would power on but i got absolutely no sound out of my speakers. I realized that the metra harness must need some power, so i connected that blue (amp turn on) wire coming from the metra to every single wire possible that dealt with power. I tried the blue remote wire coming out of the alpine, the yellow power wire coming from the alpine, the red power ignition wire coming from the alpine....everything.

As soon as the blue amp turn on from the metra gets connected with power, i get wonderful sound from my speakers and all is working well EXCEPT:

at this point whenever i hit a button on the head unit that switches something or requires power (hitting the source button to change from Tuner to CD for example), there is a large "pop" heard through the speakers. This happens when I hit a majority of the buttons on the head unit. Also, when i go back to tuner it will say Tuner, then it takes a half second to get the station signal, then it pops, then music starts playing, it pops once more...then it plays fine until I hit another button on the head unit.

Basically, i think that there is interference between the bose amp and the alpine head unit. That is the whole reason i reasearched and bought the Metra 1787..it is supposed to allow you to connect aftermarket head units to amplified systems.


PLEASE, SOMEONE WHO HAS AN AFTERMARKET HEADUNIT AND HAS USED THE METRA AMPLIFIED HARNESS, PLEASE HELP ME AND TELL ME WHERE YOU CONNECTED YOUR WIRES, ESPECIALLY THE BLUE "AMP TURN ON" WIRE.

i'm really frusterated right now and desperate for help. i have been waiting to install this thing for a week, i finally got the time and it POPs...

 

Thats weird. i have a pioneer avic n1 with no popping. Although i didnt use the wiring harness with rca's like you did. what i did was kind of make my own by cutting the bose one from the car and matching it up with the aftermarket wires. The blue wire with teh white stripe should be connected to the blue wire with white stripe from your alpine- thats your remote turn on lead. There should be another blue wire coming out of your alpine blue in color, labeled with (att) that has somthing to do with phones dont connect it to that. Ill do some research and try to get back to you. Happy Holidays Sorry i couldnt help.

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amp turn on is the remote wire

 

ok so i had the amp turn on correctly wired to remote wire...i just didnt make it a perminent connection because i was getting that popping noise.

i read somewhere a ground loop isolator might solve this problem....i saw a picture of one though, im not sure how i would hook it up.

 

Hi,

I'm having the same problem with the stereo in my '97 A4.

I replaced the factory head unit with a blaupunkt head unit (I swapped the acc and constant wires as they were different in the factory harness and the blaupunkt harness). Other than the annoying "pop" everytime I change the source from CD to Tuner, etc. everything seems to work fine.

Anyone come up with a solution for this yet?

- Brandon

 

This problem cannot be fixed. You will need to cut out the factory Bose Amplifier to stop the pops etc. Some decks are better than others in that they dont cut off signal everytime you hit a button.

The Bose amplifers use a different type of balanced input which aftermarket decks aren't compatible. Bypass the amplifier.

 

Yeah in my car I had to run brand new speaker wires to all the back speakers (the front ones worked fine but nothing from the back). After running all the wire it sounded GREAT!!! I am thinking about getting a second amp for all the speakers. That way I can run a 5.1 surround sound system with my Jensen in-dash DVD player!!! THAT WOULD BE SICK!!!

Josh

 

mine worked just fine with the stock bose amp

 

which wire is the acc from the car