C.Drive motor works in forward mode but does not reverse, blower motor runs...
1.If computer dot (second one from left) does not come on, check program to see if set for reverse.
2.If set for reverse, replace computer.
3.Check for voltage across the coil of the reversing contactor located in the rear panel box. The contactor according to your diagram is CR3, also the markings on the coil are A1 and A2.
If there is voltage, replace the coil or the complete contactor.
If there is no voltage, check for voltage across the two (2) BS3 terminals on the arc suppressor (A.S.) board.
If there is voltage across the two (2) BS3 terminals and no voltage across the coil of the reversing contactor (A1 and A2), the problem is faulty wire(s) or termination(s) between BS3 and the contactor coil.
4.If there is no voltage between the two (2) BS3 terminals on the arc suppressor (A.S.) board, check for voltage across the two (2) AS3 terminals on the board.
If there is voltage across the two (2) AS3 terminals and no voltage across the two (2) BS3 terminals, replace the arc suppressor (A.S.) board.
If there is no voltage across the two (2) AS1 terminals, the problem is faulty wire(s) or termination(s) between the arc suppressor (A.S.) board and the computer 9 pin connector no. 9, or a faulty computer.
D.Blower motor does not operate, drive motor runs...
1.Check for voltage across terminals A1 and A2 of the impellor contactor. This is the single contactor in the rear control box.
If voltage is present check for voltage across the blower motor. If there is voltage at the blower motor replace the motor.
If there is no voltage at the blower motor, the problem is faulty wire(s) or termination(s) between the contactor and the motor.
2.If there is no voltage present at A1 and A2 of the contactor, check for voltage across the two (2) BS1 terminals of the arc suppressor (A.S.) board.
If there is voltage present at the two (2) BS1 terminals, the problem is faulty wire(s) or termination(s) between the two (2) BS1 terminals and the coil (A1 and A2) terminals.
If there is no voltage across the two (2) BS1 terminals, check for voltage across the two (2) AS1 terminals.
If there is voltage across the two (2) AS1 terminals and there is no voltage between the two (2) BS1 terminals, replace the arc suppressor (A.S.) board.
3.If there is no voltage across the two (2) AS1 terminals, the problem is faulty wire(s) or termination(s) between the two (2) AS1 terminals and the computer board 9 pin connector no. 7, or a faulty computer.
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