The owners manual shows a cooling fan relay (45) in the fuse/ relay box under the hood. The same type , & part # relay operates the headlights high / low headlights circuit (relay #46).
Is there an electric engine cooling fan for a 4.2L engine on a 2005 Trailblazer on 2005 Chevrolet Trailblazer
yes. it is controlled by pcm even though it is driven by a belt.