Trailblazer Fan Clutch Wiring Diagram. Imc audio 71 2003 1 19 wire harness for 2002 2009 chevrolet trailblazer factory radio re install multi color com. There are 2 of these relays next to each other, the other one is for the cooling fan clutch.

1) remove the cooling fan assembly and place it on a workbench. Attached is schematic for cooling fan/clutch. You can switch them to see if the lights come back on, they are relays 45 and 46.