I think that this is probably correct.
You have two Secondary Windings.
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The Brown to Brown/White is a separate winding.
Brown to Brown/White is 19 VAC at 2 amps and this is probably the power for the circuit board.
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This winding is multitap to provide multiple voltages.
Blue to Blue/white is 37.5 Volts AC at 6 amps and this is the power for the cell.
Blue to Yellow should be 37.5/2 = 18.75 Volts AC.
Blue/White to Yellow should be 37.5/2 = 18.75 Volts AC.
Orange to orange/White is 32.5 Volts AC.
Orange to Yellow should be 32.5/2 = 16.25 volts AC.
Orange/white to Yellow should be 32.5/2 = 16.25 volts AC.
Blue to Orange = 2.5 volts AC.
Blue/White to Orange/White = 2.5 volts AC.
Blue to Orange/white = 35 volts AC.
Blue/white to orange = 35 volts AC.
Verify all voltages. Note Voltage is AC.
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With all power off, check resistance and post readings from:
Brown to Brown/White = ________Ohms.
Brown to Blue = _________Ohms (Should be O.L).
Blue to orange = ________Ohms.
Blue to yellow. = ________Ohms.
Blue to orange/white = ________Ohms.
Blue to blue/white= ________Ohms.
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