i wouldnt say no power drain, no such thing as free energy, an elecric motor will simply put more load on the elecrical system, causing the alternator to work harder,
ie. you still get 'power drain' on the motor wether you use mechanical or electical waterpump. it would be interesting though to see how much difference in 'power drain' the two setups would have.
good to hear you sorted ure issues out mate!