Your detonation sensor "Knock" is designed to retard the timing when you run into detonation "spark knock" conditions. Remember the old "Pinging" noise on acceleration? If it's working it should stop that. You can take your timing light and while watching your timing mark have someone to tap around the sensor and watch it retard the timing.
So you do not want to tap into the wiring of this sensor and create any resistance problems because you will probably end up with timing problems.----------