I just did this repair on my 96. There are multiple somewhat tiny metal crimps that GM uses to fasten the wires together that had rusted away. The crimp on the blue wires rotted on mine. What I did to isolate the area was I turned on the headlights and then pinched the taped wire in front of the radiator with my fingers until the drivers side headlight came on, when I let the wire go the light turned off. So I found the area the bad crimp was in by doing that. I then unwrapped the tape from the wires in that area and found the rotted crimp point. I also found one additional crimp close by that was pretty rusty so I fixed that one too. Before doing that though I wasted $91 on a multifunction switch.