Thanks for reaching out.
To measure the winding resistance, separate the multi-pin connector from the alternator and, using your multimeter, measure the resistance across each pair of white wires on the alternator side of the connector. A reading of 0.46 ohm should be obtained in each case.
Are you receiving a reading of infinite resistance?
The rotor coil can be checked in a similar manner, by making the meter connection across the green and brown wires in the connector.
A reading of 5.3 ohms should be shown.
Please let us know your results.
Thank you for your cooperation,