Is it really clogged, or is the 2nd gray tank full??
Most fivers have 2 grays, one for the galley (kitchen) and one for the bathroom.
It wouldn't be the first time I've heard someone say their sink was clogged and they never knew there where 2 handles and tanks to dump......
Steve and Vicki
2011 Dodge 3500 CTD Outdoorsman
2013 Columbus 320RS-ITS HERE!!