Through-frame record: is negative voltage a fault?
Original fictional reversing electric drive TF-TRAIN. Supplied opposite-direction records with fixed A-to-B point order.
Customer says: The meter was negative during retract. Does that mean the ground is bad?
Original simplified reversing circuit. Direction labels and numerical values are exercise data, not OEM service specifications.
Tests you can run
- Read the original reversing-circuit contract
- Read fixed-point direction records
- Read the alternate signed direction chart
- Read the corresponding supplied motion observations
- Read the earlier intermittent complaint
- Read an unmarked old meter photograph
- Read the battery purchase date