Field Coil Open Test
WARNING: This page is about a different car, the 1998 Pontiac Bonneville, 1998 Oldsmobile Regency, 1998 Oldsmobile LSS, 1998 Oldsmobile Eighty-Eight, and 1998 Buick LeSabre. However, it is still accessible from the selected car via links, so may be relevant.
Remove armature from frame and field assembly. Using self-powered test light, place one lead on field lead connection and other lead on one insulated brush. See Fig 1 . Test light should illuminate. If test light does not illuminate, field coil is open. Repair or replace field and frame assembly. Repeat test for each insulated brush.