Try adjusting the pressure switch as suggested and let us know what you find. It should straighten out the issue.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 350 ISC w/ Banks = 450Hp & 1330# torque
06 Saturn Vue & 06 Chevy Z71 4x4 toads