I assume you mean HWH jacks. What series do you have 210? If you post what model you have with a little more description of the problem you may get some more reply's. Do you mean you can't extend the jacks to level the MH? or you can't raise the jacks in the store position? I would start by checking all the cables to the solenoid, HYD pump and battery to make sure they are all clean. Once you have cleaned all connections. Fully charge chassis battery then try to extend the jacks and report what happens.