You don't need to "drop down the amperage", as the motors will only draw as much current as they need from the transformer. What do the pumps do when connected? Nothing? Run slowly? Just sit and hum?

Have you measured the voltage at the motor terminals when it is connected? Are you sure that the pumps are designed for 12VAC power, and not 12VDC?

[This message has been edited by NJwirenut (edited 06-03-2004).]