ATF: Big Country - Docking Center Gray #1 Will not open

Would like to know where to start to find out why pulling the #1 Gray tank handle does not open the valve to drain the tank. The handle pulls the cable but the valve does not open. Is this something I can easily trouble shoot myself or will I need to take it into my dealer. The unit is still under warranty, but I hate to haul it in 60 miles if it's easily fixed. Thanks Don Chisholm Canon City CO

Gray #1 should be the bathroom sink and shower. If you remove a few of the screws holding the underbelly coroplast (near the UDC), you should be able to see the #1 Gray as well as the black tank valve. The bigger pipe is to the black tank. The 1 1/2" is to the gray. The cable may have some loose at the valve. If you can reach it without taking the entire sheet of coroplast down, it might be worth doing it yourself. If you can't get to the valve easily, take it in to the dealer. If you have an auto creeper, and a cordless drill with 3/8" socket, it'll make things a lot easier.