Somehow, the Fan Clutch senses the Ambient Air Heat Transfer Rate from the
Radiator and ENGAGES, causing MORE Air Flow across the Condenser/Radiator
interface.

(As the air flow from the Radiator HEATS UP, the Clutch engages Increasing the Heat transfer rate of the Radiator.)

[It's a Bi-Metallic Strip that functions as the "Engagement".]

__________________
'84 300SD sold
124.128