Series Coil Open Test

Using self-powered test light, place one lead on series coil terminal connection and other lead on insulated brush. See Fig 1 . Ensure series lead or positive brush is NOT touching any ground during check. If test light fails to illuminate, series coil is open and requires repair or replacement. Repeat test for each insulated brush.

Fig 1: Testing Series Coil For Open

Courtesy of GENERAL MOTORS CORP.