Does anybody know the wiring diagram for the amplifier in a 99GS 300? I called McGrath and they said they didn't have it! I'm trying to install a aftermarket radio but i need to know which wire goes where? Please Help!

 

If I remember correctly, If you are installing a new HU, you prolly don't want to use the stock amp. If you locate the stock amp (by the glove box) the output wires has the regular toyota plugs. You can just get a harness and wiring should be cake. I personally have not looked into this because I just upgraded to a newer stock radio, utilizing the amp. Which is a PAIN in the butt because of the different plugs!

This information is just from reading other posts, when I was researching on my upgrade. So i'm not 100% sure. I hope it works outs.

Lastly, WELCOME to CL!

 

I do have a diagram that might help you out. whats your email?

 

pivaralgs300@comcast.net

 

yeah i bought a Toyota harness and the wires are not the same it wont power up the guy at bestbuy told me that that was not the right harness so know i'm stuck! THank you by the way!

 

Have you checked the other side of the stock amp? Does the toyota harness fit onto those connectors?

The toyota harness (2 plugs) should fit onto the plugs that were once connected to your stock radio. But the wiring is not the same, you would have to swap the wires around. In fact i'm not sure how well the stock amp would work with any aftermarket HU because it amp uses BUS lines to control it. We won't get into that. Some people has gotten the stock amp to work but most just bypass it entirely.

You should have the diagram in your email!

 

Should of asked you in the beginning. Do you have the stock pioneer radio or nakamichi upgrade?

 

guys i happen to be an installer for circuit city been doing it for about 3 yrs now and you'll have to do an amp bypass ive been looking at mine i believe you have to extend the toyota harness to the passenger kick panel where the stock pioneer amp is and is should plug up to output side
just to be sure ill be outta town until sat but sat. night i WILL check my theory on my car ill test it out and let you all know the toyota harness on the back of the radio has line level ouputs on it not speaker level i've already tried to make an amp intergration harness didn't work

so ill hit this thread back sat night

 

Can I get that wiring diagram 2?

 

Back of the pioneer radio:



Pin-outs of the pioneer amp: