2001 Dodge Ram 5.2L Oxygen Sensor Fault Codes P0132, P0135, P0138, P0141 - No Heating Voltage After Replacement

I'm seeking help with persistent oxygen sensor fault codes on my 2001 Dodge Ram 5.2L engine: P0132, P0135, P0138, and P0141. I've already replaced both oxygen sensors and reset the ECU multiple times, but the codes persist. I've also checked and replaced the wiring harness, yet the issue remains. My suspicion is a wiring fault—specifically, I'm not detecting any voltage from the heating circuits of the oxygen sensors. The sensor heating wires are critical for proper operation, and without them, the engine control module (ECM) registers faults. I've searched through repair manuals and online resources but cannot locate a clear electrical diagram showing the routing of these heater wires or their connection points on the PCM connector. I need to know exactly where the wiring runs from and how to identify each wire by color code and terminal number for proper diagnosis. Any guidance on locating this information would be greatly appreciated.