ATF: Big Country - 3490RB tank question

Can you please tell me how the holding tanks are set up in my rig? Are both heads piped to a common black water tank? Where does the sink in the 1/2 lav pipe to? Is the dump valve in the rear under the steps only for the rear grey tank? Thanks in advance, John

I have forwarded your questions on to our service dept. They will be able to get back with you.