Last night I replaced the factory deck with a new Panasonic Mp3 player. I used Scoche wiring adapters to blend the new deck to the stock wiring adapters. Here's the problem. When I play a cd or mp3 disk I get volume from the front speakers like I would expect, but nothing from the rear speakers. When I play from the radio I get volume from the rears and very little volume(though it does come out) from the front in comparison to how much volume there is when playing a cd. In all cases the volume is set at level 18 and the fade and balance is centered for both radio and cd. To add to the mix...I have a broken power antenna that makes an awfull grinding noise when it activates. Since it is stuck in the raised position and I don't mind not having it go up and down I left off the power lead to it from the new head unit. Only problem is then the rear speakers would never come on.

Whats goofy in this wiring of a stock deck that I don't know about that could be causing this?

Thanks
David Wagner

 

Hmm. Ive wired a few more than a couple decks in my day, Ive never heard of this. What I would suggest would be checking all ur connections. Make sure their clean, not touching, If that doesnt work. Id prolly say its the wiring harness.

 

I put in a Panasonic in my 90 4Runner and I have a simular problem. The rear speakers worked when I had the stock deck in, then when I put the new Panasonic in the rears stopped working!! I checked all the conections and there were fine. Just gave me a reason to put an amp under my seat and get new rear speakers!!!

Sorry I could be any help...

 

If there is a factory amp you need to bypass it.
Wire it straight to the speaker wiring harness not the amp.

 

I had the same exact problem.

Here's the fix:

Each rear speaker is powered by a small amp included in the speaker enclosure. Somehow, (and to this day I do not know how), these amps are remotely kicked on when the factory stereo turns on, however for some reason they are NOT kicked on after you replace the head unit.

To bypass each amp, you must pull the rear panels off and cross the wires. The wiring colors that go IN to the amp shoud be the same as the ones going OUT from the deck. From there, there is a red and white wire that comes OUT of the amp IN to the speakers. I forget which one is postive, but I think I just guessed and used the red and it's worked fine. Connect the red wire to which ever wire going IN to the amp is postive and same with negative wire.

 

I had the same prob in my '91. I was too lazy to pull the back panels off, so I just put two 6x9s in the back in small boxes. This gave me better sound, obviously, and allowed me to aim the speakers into the cabin.

 

PROBLEM SOLVED Yahoo!!!!

After a bit of internet searching I found an installer guide. In it I read that you must use the amp power wire instead of the remote antenna power wire for the systems to work. Since antenna power only activates when listening to the radio on newer decks it throws off how the factory amps turn on and shut off. After making the switch everything works like it should; except now I have a much better head unit

 

what did you do to fix this? I have a similar problem in my 94.. I just installed a sony hu, I bypassed the stock amp and everything, when I tested it before mounting it completely the sound was great, but when I put it all the way in and screwed it all together there is no bass whatsoever.. It seems like the amp in the hu itself is not working now.. I think I need to check my ground but I don't think that would cause this problem.. Any help here would be great.. thanx
jake

 

I found the guide on www.installdr.com From there I learned about the wiring issues with the power leads. I did not bypass any factory amp according to the site and things work great now.

 

 

I am new to this board. If there is a section I can upload a pic to I'd be happy to share. I don't have a personal site that I can host my own pic though.

I got the entire setup from sounddomain.com. Everything was definately plug and play (once I figured out the wiring issue) using their "What fits" product selector. They threw in free install kit, harness adapter, and connector kits too. I highly recommend them.

The head unit is a simple Panasonic CQ-DP383U MP3 Player. It fits perfect with no dash modification.

 

I don't mean that I bypassed anything.. I just used a wiring harness to get by the factory amp..

 

i just got finished fixing this little problem. after returning 2 head units and ahving my friend who works at a car stereo shop look at it i found the same thing as the OP. If you just connect the amp turn on switch to the factory power antenna lead, the rear speakers will work all the time.
It made no sense to me that the speakers were working when the radio was on but not when cds were playing. This worked so until I get an amp all is cool.