Before you ask...

[2K1Xplorer]

I have done a few installs in my day. I found two great ways to get thought.

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Nice site with details for a lot of cars.

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Great site for getting into custom wiring.

 

[ok89]

Particularly:
Head Units
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[AQexplorer]

i wish i had known of those places when i was installing my system!!!

those look like a ton of help