The Best Way to Splice Wires Without Soldering in a Car Radio

Apart from soldering, the preferred method of connecting your new car stereo harness to the vehicle's harness is the butt connector. These are open at both ends, covered with an insulating plastic to prevent inadvertent shorting when coming into contact with metal, and come in a range of sizes to fit most wire gauges. For most stereo installations, the blue connectors -- for 14- to 16-gauge wire -- are perfect.

Installation is simple. Strip about one-quarter inch of insulation off of each wire to be connected. Insert the first wire into one end as far as it will go and crimp that side only. Repeat for the other wire on the other end of the connector. For best results use a crimping tool, but a pair of pliers will work in a pinch. For added insulation, you can slide a piece of heat-shrink tubing about one-half inch longer than the connector over one of the wires before crimping, then slide it over the finished connector and shrink using a match or lighter.

Also known as plier tap connectors or by the 3M trademark name Scotchlok, splice connectors are an alternative if you have difficulty getting a good crimp with butt connectors or with stripping insulation off of the wires. Slide the existing wire into the open side of the connector, then put the end of the wire you wish to connect to it into the other side. Then use a pair of pliers to push the metal tap down into both wires, flush with the body of the connector, and snap the cover over the tap. These use the same sizing convention as butt connectors, so blue will be the correct choice in most cases. Heat shrink's bulkiness makes it difficult to apply to these, but you can wrap with electrical tape for extra insulation.

If you plan on removing the stereo to use in another car or aren't 100 percent sure of the correct wiring, you might want to go with bullet connectors. These give you the ability to easily disconnect and reconnect wires. Sized the same way as splice connectors, these install much like butt connectors: strip and crimp. They can be covered with heat shrink as well. Simply cut the shrink tube off with a knife when you want to disconnect in the future.

Follow all recommended safety instructions when installing a car stereo, particularly disconnecting the battery before cutting, splicing or stripping any wires. While the likelihood of encountering enough current to be harmful while installing a stereo is small, disconnecting the battery eliminates the possibility of shock.