I looked up the Marco UP2A pump. According to the tech specs it draws around 3 amps @ 12 Volt. AFAIK that is too much for the pump switch that is normally installed on the A54. Did you remove this or did you something else to make this work.
It does seem to be more power hungry than the original solution. This I why I'm going to test the March pump. But I'm using sea-water for the cooling.