Searching for a Electrical Schematic for FORKLIFT Hyster30 Electric

I'm helping the mechanic trouble shoot my immobile Hyster30. It's done this once before; just won't move. I heard a slight click sound when I pressed the throttle pedal. Moments later it started to drive again. Now, 2 months later, it did not come back to life. Lots of symptoms, noises.... Fully charged, it made the typical sound of the power steering pump being on then it went off a spilt second later. Next morning, when the key is turned, all that happens is a metronome like click, click ,click click...... We traced power, 36volts back to the board. Mechanic says only 17volts comes out the other end. I DON'T UNDERSTAND THAT YET. He says it may be a transformer in the board.... ANYWAY, NEXT STEP FOR ME IS TO FIND AN ELECTRICAL SCHEMATIC ONLINE ANY SUGGESTIONS OR LINKS OR ANY CLUES YOU CAN PASS ON WOULD BE APPRECIATED