I replaced my stock am/fm cass radio in my 94 4runner second gen. with a new Poineer 3900 cd/mp3 player. I bought the wiring harness and used it to connect to the existing plugs however now my rear speakers dont sound like they used to. Any ideas on what I may have done to cause this.

 

probably because the rears are getting more power than they were with the stock radio, making them distort...i would either upgrade all the door speakers or get some bass blockers if you insist on keeping the stock rears...

 

Thank you for the info. I have one last question. when I used the exiting plugs from the vehicle I had to unplug them from what looked like a small amp box under the dash. Is that what was powering the rear aspeakers? If so do I need to replace with a new amp or do I just need to get better speakers for the rear?

 

If that was an amp, I promise the amp built in to your new deck is way more powerful than than what you unplugged from.

 

yeah, like stated before, the new deck will more than likely be more powerful than the stock amp...but yes, if i was you, i would at least replace the rears, and also the fronts if your budget allows, as that's the way you'll get better sound...