Hello Kimberranch, You’ll want to check and make sure whether the 24V ports were for a power source or a rain sensor on your old Toro timer. We have 24VAC out terminals for a pump start relay connection. If they are just for a power source then you wouldn’t use them, because the transformer is already built into the timer. As for the 12V port you will need to contact Toro to find out what it was for exactly, and then we can assist you after that. Please let us know if you have any further questions.