Fresh water pump

[mac62]

I have a 2002 3300 SCR, the fresh water pump will run, build up pressure then stop, all normal. Issue is when i open a faucet the water pressure is good for about 1 second, then the pump continues to run but the water pressure is very very low. Shut the faucet and the pump builds pressure and stops.
Any advice?

[mmwjr]

Most pumps have a filter on them that will clog over time and restrict water flow. I would start here. Have tested this at different faucets?

[mac62]

Yes, poor pressure at all when using on board tank

[mmwjr]

Ok if the filter is ok the pump is most likely weak and needs replacing.