As mentioned earlier, we have installed the ISIS Intelligent Multiplex System (www.isispower.com) to manage all the power functions of our 89 Mustang.  We were basically able to remove all of the original factory wire harness…  we did however keep the pigtails and short harness for the front and rear lights, this made wiring them up a little faster.  Many more details to come in how we wired up our FOX but for now check out the cool feature you can use with the ISIS system, which is a true ‘push to start’ system, no key needed.  Basically the system handles the procedures.  When we depress the start button (hold it down), ISIS turns on the ignition (ACC), a power (positive) connection is made to the Ford Racing Control Pak ignition input wire, then ISIS waits 2 seconds, then it sends power to the starter wire connection on the control pak.  The car then turns over to crank.  Then once the car starts, we releasethe Start button and the car stays on and running.  To turn the car off, you simply depress the start button again, and ISIS kills the ignition signal to the control pak and it turns off the motor. Who needs keys!?  FYI – The ISIS comes with a key fob, if you depress the ‘Lock’ button, then all ignition and starter signals are locked and the car cannot be cranked, thus it cannot be hot wired…  sorry! 😛