Originally Posted by jakenbacon
your power supply is only rated at 5V, while the pump calls for 12V. It is also almost half the wattage required. May be causing some issues but I doubt the death of the pump. The power supply on the other hand may be a possibility. Do you have a multimeter? Check the votage coming off that power supply and let us know. Good luck
Does anyone know if the DC motors on the tan pumps are blushless or steppers? I don't know much about the electrical design of DC motors (or even AC motors). But with an AC motor if you drop the voltage the motor actually pulls more current and heats up - and this can kill a motor.
Edit: Looking into a bit more there may be controls in the tan pumps so that any voltage (up to 12V) can be used - But I would expect that if the pump still runs at the same speed that a lower voltage would result in higher current which would smoke your adapter.