[RussWhite]

The problem I described involves voltage to the contractor that runs the hydraulic pump motor. In my case with no alternator the voltage was right on the border line. It might run or it might not. Since the pump is shared between front and back on my coach it could result in one or the other or both not running. The problem can be diagnosed with a voltmeter on the coil of the contractor. Observe the voltage when you try to move the slide. If there is voltage - say in excess of 9 volts, but less than 10 or 11, the contractor may just not have enough magnetic field to energize. If you are seeing that, then some way to increase the voltage to the contractor is required. My little relay between the board and the contractor did the trick.