AC compresser engagement ?

[TONY TAT2]

base 1.8 /09 . How do ya tell if the ac compressor is engaged ? I see the serp pully,than a 1/8 " space then a outboard solid disc. Im used to see'n the gm clutch type where theres a outer disc/clutch thats stationary when off,spins when ac/defrost is on. thanks !I found some picshttp://cas07.businessflow.ms/C...a9989that looks like mine,the outer disc doesn't spin free.is the electro clutch "inside" the compresser maybe by where the conector plugs in?