Wiring diagrams for the M2 frequently highlight specific "hot spots" where electrical failure occurs due to high current draw and environmental exposure: Freightliner M2 AC Blower motor not working ???
If you are diagnosing a "No-Blower" condition, the diagram is essential but only half the battle. Freightliner M2 Blower Motor Wiring Diagram
(which includes an internal or external resistor/regulator). Blower Motor Pinout & Wire Colors Wiring diagrams for the M2 frequently highlight specific
| Function | Wire Color | Gauge | Connector Location | | :--- | :--- | :--- | :--- | | | Red or Red/Black | 10 AWG | Blower motor relay input | | Ground | Black or Black/White | 10 AWG | Blower motor chassis ground | | High Speed Trigger | Orange or Dark Green | 14 AWG | Between relay coil and switch | | Switch Input (Low-Med) | Light Blue, Yellow, Tan | 16 AWG | From resistor to switch | | Resistor Output (M1, M2, M3) | Brown, Purple, Grey | 14 AWG | From resistor to motor negative side | Blower Motor Pinout & Wire Colors | Function