98 Toyota Avalon Stereo Wiring

I am in the process of connecting my new head unit to my toyota avalon.  I have completed most of the wiring which follows in this order.  The new head unit will run through the factory amplifier and out to all the speakers.  The reason I have chose this method is to retain the use of my factory subwoofer.  I have completed most of the wiring antenna, amp power, memory power, accessory power, but I am in need of a wiring diagram so I can connect my speakers with the correct polarity.  I know I could use the old battery and wire method, but that is too time consuming.  If someone could provide me with this particular wiring diagram [ Factory Line Amplifier Output to Factory Head Unit] I would appreciate it.

Thankyou for your time.

--aznivasion

Try this

https://www.the12volt.com/installbay/detail.asp?info=alarm&year=1998&make=Toyota&model=Avalon&ID=18946&type=Stereo

You can try the local Toyota dealership or try to contact Metra or American International, Best Kits or any other wiring harnes manufacturer for this information.

The wiring diagram doesn't entirely match up.  There are several of the same colors and both greens look the same... Even if it says light green or so.. It's just green with grey dots.

From the head unit to the amp the wires are as follows:

Front left + = Green

Front right + = Red

Rear left + = White

Rear right + = Yellow

This system is using a single ground signal to the amp and it is brown.  There are two brown wires in the harness for the head unit ,but only one in the harness for the amp.  The second brown wire in the head unit harness is for system ground.

thank you for the info.  I have been looking for it for a long time, now that I have all the positive polarity's to the speaker it should't be that hard to find the negative polarity's.. thank you again for the info...

--azninvasion

it would be nice though if you could provide me with the negative pinouts too so i won't have to use the old battery and wire method to find out which pinouts are negative...

Since this system uses a factory amp, it does not have individual grounds for each speaker.  It is only using a single ground for all the speakers. 

I don't recommend using the factory amp.  If you are trying to retain the factory sub, use an aftermarket amp and wire direct to the speakers.  Anything else is going to cause you problems.

I decided to contact bestkits.com for information on installing my stereo and this is what I got.  I found out that I probably had a JBL premium stereo in my avalon and the following email outlines what you will need to upgrade your head unit.

Hello,