Engine fan control valve for M939 and M939A1 series 5 ton truck (NHC-250 Cummins).
P/N CA200046, CAS190, 11669644. NSN 4820011491317. OEM part.
Valve senses the coolant temperature and applies or releases air pressure to the fan clutch (Applying air pressure engages clutch). Sensing trip point is factory set at 190F and is not adjustable.
Not for the M939A2. For late model trucks see p/n CA200011.