68' Charger A/C controls not working...

[StockMan]

I have a 68'charger with A/C.  I recently completed a restoration of the dash and installed a new vacuum control unit in the heater/AC controls (the old one was cooked).  I bench tested the system and everything seemed to work properly.  The dash is in the car now and other day I turned the key on I decided the fan came on as it should I then pressed the 'Off' slide and the fan stopped.  I'm not sure if this is supposed to happen?  This is one thing I didn't try during my bench test.  Anyway, I figured if I pressed the 'Heat' slide, or 'Defrost' the circuit would again be closed allowing the fan to start up again but it doesn't.  I did connect the fan directly to a power supply and it works.  Also, none of the fuses are burnt. 

Does anyone know if the hitting the off switch cuts power to the fan?  Has anyone experienced problems in this area?  I don't have the A/C installed yet so I don't know how it would be affected.  Any ideas?

Thanks