If the battery isn’t working, your best option is to look for an auto parts shop for a professional diagnostic, as a home diagnosis isn’t always accurate. [1] X Expert Source Jason ShackelfordAuto Technician Expert Interview. 11 June 2019.
If this wire has no power, then your ignition coil is not receiving current. You should check the wiring from your ignition switch to the coil for breaks in the wire and repair them. If this wire has power, then the wiring from the ignition switch to the coil is working properly and you can move on.
Trace the negative wire all the way to the ignition module looking for any breaks in the wire. If there are any breaks in the wire, they must be repaired. If there are no breaks in the wire, use an Ohm meter to test the resistance of your ignition coil. Your service manual should specify resistance values for the primary and secondary coils. If your coil does not register the proper resistance, then you will need to replace your ignition coil.
If you observe no current then your pulse generator has likely malfunctioned. If this is the case you will need to replace it. If you observe a current then your pulse generator is likely operating properly. This may indicate that your ignition module is not functioning and you must replace it.
