Well get a multi meter and check the live wire feed to the relay has life when the ignition is first switched on or whilst your cranking it should show constant 12v pos, if that is ok then check your new loom pos is connected fine, then check the inline fuse iis ok this will determine that you have a good trigger feed and the 12v live to the relay. I take it the earth for the pump and relay is through the boot floor ? If so check that connection, if all ok get someone to crank the car whilst you hold the multi meter on the pump terminals if that shows 12v then the pump must be faulty, can't really be anything else as its a simple circuit.