Thanks for all the suggestions. The best way to describe the problem would be like a garden hose with a pistol sprayer on the end. Turn the water on a 1/4 turn. It filld up the hose and builds up pressure. Squeeze the pistol grip and you have the full pressure as if the water was turned on all the way. As soon as that initial burst is out, back to that 1/4 trickle. Hope that makes sense. Now my theory, I have full pressure from either city water or tank/pump, the blockage is just upstream of where all the water is fed into the system.
2006 42' Country Coach Magna VanGogh
525 CAT, Build # 6553 Pulling a 2011 Chevy Tahoe