AC Switch
 

On a 72 with AC, I have an issue with power to the relay in the smugglers box. When I turn the 3 speed switch to the on position nothing happens. However, if the switch is turned to the on position and I manually close the relay switch, something the solenoid is supposed to do, the system works...fan is on and the electric clutch for the compressor activates. All this while the engine is running...

Could it be the 3 speed switch or might it be something else?