My son's 1998 Olds 88 started acting up the other day. The speedometer was reading erratically, and the transmission was jumping back and forth between gears. I put a new vehicle speed sensor in it yesterday, and the problem cleared up. Now it's back at it again. I suspect that the real problem was in the wiring to the original sensor, and not the sensor itself. I suspect the insulation has worn through and causing occasional/constant erratic signals. Question.... The two wire lead that plugs into the sensor is a fairly wire, that comes from inside an insulated bundle. I want to replace this with a new pigtail. Does this sound like the next likely step in the repair, and how can I access this without damaging other wires is the bundle? Would I be better off trying to isolate the existing wires with electrical tape before I resort to replacing the wiring?