Low water pressure, park pressure and hose good

[CaptainGizmo]

We didn’t touch the filter because we don’t drink from the tap, I think there is some kind of pressure regulator where the hose connects to the rig, all I know is when I press it, water comes out of the fresh tank how do I know it’s not that? Nevertheless I’ll check out your videos it can’t hurt to try it. Thanks

Totally at a loss as to what or where you're referring to. I'm afraid for us to help you, you'll have to start posting pictures of what you're doing. It will really help us help you.

But, using my gut...if you're pressing on a "BUTTON?" on some type of unit that causes your tank to overflow, then this is the Auto-Fill solenoid and the button you're pressing is a manual bypass. If I am correct, then this is not relevant to your issue.

It's simple in the fact that:

1. You've got GOOD pressure AND flow from the hydrant.
2. Some, but not ALL, of your fixtures have GOOD FLOW.

Therefore, you've got a plug in your system; either at a filter (anywhere in the supply system), or a screen (faucet), or a mixing valve (shower).

There can be multiple points of clog, so you'll have to clean and/or replace each one. NO Coach/RV is immune to getting jacked up from sediment!! I recently helped a couple Newell owners who failed to see the importance of running filters AT THE HYDRANT before a drop of water gets into their coach. They're ALL happy owners of a filter and soft water tank now!
And, NO, a simple Camco filter doesn't do the job of full filtration on a modern large-volume coach.

BTW, if you get to the source of the junk and can't clean the calcification, use CLR or a 50/50 Vinegar/Water solution to soak them clean.