1996 Chrysler Town & Country

Heat and A/C control head does not seem to be switching the various mode doors. I have both heat and A/C however all air is directed to the defrost duct on the dash, The recirc button still works, but still goes only to the defrost. I have tried replacing several of the relays under hood, but no change. Where are the vent door actuators? Is there a fuselink or other possible cause. I have checked fuses and haven't found any bad! Is there a place to get a detailed wiring diagram for this circuit? Any help with be greatly appreciated! Thanks Les