Armature Test: Ground
WARNING: This page is about a different car, the 1995 Jeep Wrangler, 1995 Jeep Grand Cherokee, and 1995 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
Using growler or a self-powered test light, touch one lead to armature shaft and other lead to each commutator bar. See Fig 1 . If light glows at any point during procedure, armature is grounded. Replace grounded armature.