A new car stereo breathes new life into the driving experience, supplying more power and features than the stock unit you're replacing. Wiring the antenna and other leads in the new radio's harness is more straightforward than it may initially appear. Aided by color-coded aftermarket wire harness adapters, connecting the new stereo to the existing vehicle is done without hacking up wires.
Stock Stereo Removal
You may be eager to get that new stereo in the dash, but first the old one has to come out. Source a vehicle schematic showing the location of the various screws and clips retaining the radio trim bezel around the stock head unit. Remove the screws and place them in a cup holder or other secure location. Carefully pop off the trim, exposing the hardware holding the stock radio bracket in the dash. Remove these as well, keeping them isolated from the other screws to avoid confusion. Remove the radio and disconnect the wire harness. Pull the antenna lead from the back of the radio. Remove any brackets connected to the stock radio, since you may need to screw these to the new dash kit required with the upgraded stereo.
Wire Harness Wiring
Note the label affixed to the top of the new stereo. This should provide you with the colors and designations for the wires in the stereo's harness. Match these colors and functions with those on the aftermarket harness adapter. Pull off the prestripped flying leads from both harnesses. Crimp the matching wires together with a crimp tool and insulated 16 gauge crimp connectors. Plug the radio's harness into the back of the stereo.
Powered or Passive Antennas
Take a look at the factory wire harness in the dash cavity. If you have a powered antenna, there will be a wire labeled "ANT" or "PWRD ANT." This is often blue with a white stripe, but you'll want to consult the schematic to be sure. Connect this wire with the matching wire on the new radio's harness for the best radio reception, especially in fringe areas. If the radio has a lead for a powered antenna but your car doesn't have one, simply crimp an insulated connector over the bare wire lead, but don't connect it to anything.
Cleanup and Test
After all of the individual wires are crimped together, use three of four small plastic zip ties along the harness to bundle everything up. This step makes it far easier and cleaner when attempting to slide everything back into the dash. Place the new radio's mounting sleeve into the cavity of the aftermarket dash kit, then bend up at least one of the triangular retaining brackets at each corner. Slide the new radio into the sleeve until it locks in place. Connect the radio's harness to the radio, and the other end of the harness into the factory wiring in the dash cavity. Plug the antenna wire into the back of the new stereo. You will probably need a converter harness to change over the pin pattern on the vehicle's antenna lead with the universal sleeve-style antenna input on the new stereo. Carefully slide the assembly into the dash, lining up the mounting holes on the harness with the holes on the dash. Secure the new radio with the screws formerly used to hold the factory stereo in place. Replace the radio trim and any hardware. Turn on the system and adjust balance and fade, ensuring all speakers produce sound.
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