I have come across a lot of car stereo systems over the past 10 years or so. There are so many "techniques" to installing head units. everybody has their own idea of what is right and wrong when wiring up a system, but just because it works doesn't make it right.
Car Stereo Wiring 101 - A Must Read!
I asked Majestic Modifications what their idea was on the subject. How do they install so many units and always get it right?
First, if applicable, always use the harnesses. The aftermarket wiring harness will ordinarily take the guesswork out of the installation. These harnesses attach to the vehicle's premise wiring harness and gives you a color coded installation. You just attach red to red, yellow to yellow, etc. But is that all an installer should know?
Car Touch Screen