Yes, it is possible. The way these fan clutches are designed, there's a "spring" on the front that expands and contracts with heat. If you disengage the outer end of that spring and rotate it the right direction, the fan clutch will be always engaged. I've done this a few times for diagnostic purposes.
The main negative consequences: 1) greater noise as the fan will be spinning faster, 2) decrease in gas mileage as it requires some energy to spin the fan and draw air through the radiator (I think that is the main reason fan clutches were introduced -- to help nudge gas mileage up), 3) Possibly an increase in wear on the water pump (or whatever the fan is attached to) bearings. Nothing major. Depending on your reasons for disabling the fan clutch, I wouldn't let these stop you.
Another negative is sooner or later we will see colder temps, when it gets cold enough you really dont want the fan keeping the engine cold, it adds a whole other set of problems.
Look for an electric fan, Ford Taurus fans are a suitable replacement and can be found cheap at recycling yards.
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