Operation CHARM: Car repair manuals for everyone.

Primary Input Test

Fig. 1 Primary Input Test:






1. Connect a suitable voltmeter between coil positive terminal (B+) and ground, Fig. 1.
2. Turn ignition switch to On position.
3. Voltmeter should indicate 12 volts (battery voltage).
4. If 12 volts is not obtained, check for faulty battery, ignition switch, wiring or electrical connections.