i am putting a new stereo into my 05 chevy colorado and before i buy a wiring harness i need to know if i accually need one since i do not have onstar?
That's your power wire. It should go to the corresponding power wire in the wiring harness. If you are not using a wire harness, you have to connect directly to the battery (positive) - If you do it this way, you must connect an in-line fuse to give it current (I recommend a 30AMP fuse).
While it is possible to install an aftermarket receiver in practically any vehicle without a wiring harness, it's usually better to use one. 1) First of all, it makes the installation easier and more professional looking; 2) If something goes wrong, it's usually easier to isolate and diagnose the problem; and 3) If and when you ever want to re-install the factory unit (perhaps when you trade or sell the vehicle), it can be just plugged back in. Wiring harnesses are cheap and what you pay for one can save you lots of time and future headaches. I've had to correct a few butcher jobs myself, and believe me it would have been a lot less expensive if they had just purchased a $10 harness in the first place. And in the case of the Colorado, a wiring harness will eliminate the need for extensive rewiring if you want to retain factory chimes or steering wheel controls.
