Jim, welcome to Gulf Stream Owners RV Forum. You should not have any voltage potential between the two grounds. Be sure to not only check the DC side of things but also the AC side as the equipement ground is bonded to the frame as well. Good luck and let us know what you find.
Mike, Amy & Muffin, Full Timers
RVSA Certified Master Technician
iRV2.com -Gulf Stream Owners Forum Leader
2000 Scenic Cruiser
99 Chevy Silverado 4 X 4 Toad
2006 Saturn Vue AWD Toad
NASCAR #3 & #8