I would think that if you got an exact replacement monitor and installed it to the existing sensors it would give you the reading you want as long as both monitors were not activated at the same time. If however there is an inaccuracy some diodes could be installed to isolate one monitor from the other.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7