water flow at faucet only when pump is running, but flow is slow
Most RV water pumps have a pressure switch. They shut off a few seconds after you initially turn them on because they have pressurized the line. Once you open a water valve (faucet/toilet) the pump will start running again. Low flow could be caused by the size of the pump, size of plumbing, or line blockage.
boogies right. you could have debris in ur lines, an inadequate pump, or something much worse take it to a service center if its new it should b covered under warranty