[gmachinz]

That blue strip is part of the 2-wire bonded pair GMs’ supplier used in OE assembly line harnesses. The brn and blu wires are seperated at the switch and motor but inside the looming they are what’s called a bonded pair. They go to the motors. You’ll see them going to the motors on each door. Those are acrylic jacketed leads and I use updated SXL/GXL oil resistant high heat wiring in all of my repair pigtail sections and harness assemblies.