Diagnostic Aids
WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
To locate an intermittent problem, use scan tool to monitor DTC P0480 LAST TEST with engine running and A/C relay commanded on. Wiggling wires while watching for a change from PASSED to FAILED may locate the area where an open in the wiring may exist. Wiggling wires with the A/C off and ECT below 205°F (96°C) may locate where a short to ground may exist.
A short to voltage on Dark Green wire will cause DTC P1650 to set.
Cooling fan relay coil resistance: 60-90 ohms.