Sorry, Budd, I did not realize you were working in a roadster. I hope the schematic is close enough to help.
In the case of the 451, the radiator fan turns on when the AC compressor is on, not not constantly. Before ripping the system apart, I suggest you have the AC serviced. There are a few parts in the AC system that work in conjunction with each other. If something is amiss, the system may not work as expected.
Just recently, I serviced my AC system. Prior to doing so, my cooling fan was somewhat erratic. I think the AC pressure may have been a bit low. After system service, it appears to be working better.
When I suggest service, I’m not just recommending to add a can of R134A - that can result in overcharging, overtaxing the compressor, inefficient cooling, and the inability of the condenser to return the R134a to a liquid state. In other words, overcharging is often times worse than undercharging and can result in damage. A sufficient undercharged system will simply not allow the AC clutch to engage and the system won’t provide cooling.
I hope this helps