This past week my HWH leveling jack control board discontinued to light up. Jacks were down but got them up per instructions in manual of opening T valves. Now I've checked the battery power to pump motor it's okay, 40 amp fuse okay, check 6 fuses in box in front of my 2003 New Mar motorhome, which is about 12"x12" in size. All fuses okay. Removed the control box to look see, nothing there but wires connected to control box.
Where do I go next, how do I check the control box for its working?