What could cause puddles of water in the passenger floorboard when using your air conditioner but now neither the air conditioner or heater even work?

There could be two possible answers to your ?? Behind the dash board on the passerger side depending on make\model of car houses your a/c and heating system. If this started with only using the a/c it could be a broken or cloged evaperator drain. creating the a/c condensation to build up and run on the floorboard this is not very common but can happen The excess water that can not drain off can also be pulled up into the blower motor causing it to short out and blow the fuse in the fuse panel. More common problem is the heater core is housed in the same location next to the evaperator. The heater core is often the cause of the problem especialy if the cooling sys on the car has not been maintained properly over the years. another sign of the heater core leaking is the front window will fog up real bad when the defroster is turned on and you may get a bad oder also. This can short out the fan blower the same way the a/c does.