I lost my key to my 2000 ford focus but don't want to pay for another key. I have a friend that will sell me the ignition key for real cheap. I was wondering, can I cut the wire an the with the black box that holds the chip and splice it to mine will it work?
It sounds as though you just want to cut out the "black box" and try to make this work. If so, you are sadly out of luck. If it were that easy on any system which uses a security system, a lot more vehicles would get stolen on a regular basis. In most vehicle security systems, the "black box" verifies the identity of the chip in the key, then sends a "start" signal to the computer which allows all of the systems to function and the vehicle to start. If one part of the system is missing or malfunctioning, the vehicle won't start.
Unfortunately, from your description, if you want to have continued use of your car, you'll need to get a new chipped key and get it paired to your Focus. I believe many vehicle security systems can be paired to a new key at lock smiths and other such places. You can also get them paired at the dealership, but they'll usually charge you an arm and a leg to get through the process ... use them as a last resort. One of the issues with it no matter how you do it is, you have to have the vehicle and the new key on location to make it happen. You may, however, be able to find someone who can do it for you. Some security systems can be user paired, but when you've lost your key, that becomes problematic. I'm not exactly sure how the Ford Focus system works, but without a functioning key, the process is arduous if you can do it yourself at all. This is by design to help prevent theft.