HELP! Black tank Clogged

Put a cap with a water hose connection on it, Wal-Mart has them. Turn on the water and blow the clog back into tank, make sure not to overflow the tank. Then dump the normal way. I saw a RV repair man do it this way. Charged a $100 to come to site to do it.

This procedure may require two people, depending on your tank/valve configuration:

With the valve closed, connect the sewer hose to the tank with the other end open. Lift the open end higher than the tank and partially fill the hose with water. Holding the hose up, open the valve and move the hose up and down (but not far enough down to spill!) to work the water back and forth against the blockage. After several minutes of this sloshing motion, close the valve and carefully lower the hose over a bucket or the dump station port. Then with the hose hooked to the dump station port as usual, open the valve again. The entire process may need to be repeated a few times, but it usually does work.

I would add water to the black tank let soak for 2 or 3 days then try again. One of the reasons this happens is not using enough water when you flush. If that doesn't work try shoving a hose up to brake the clog. If that doesn't you might have to take off the black pipes under your unit and dig out the clog. I know it's a sh---- deal but somebody has to do it. Let us know how it goes.