The ignition amplifier is an essential part of the ignition system in your vehicle. Without it, your vehicle would be unable to start. The operation of a ignition amplifier is quite simple. It is sent a signal from the ECM or the distributor which tells it to switch the current of 8-10 amps to earth. This is essential to complete the ignition circuit operating correctly and allows the spark plugs to spark. To ensure that the ignition amplifier is working correctly, a volt drop check should be completed. 

Signs of a ignition amplifier failure could include your vehicle misfiring. This could also be caused by other key components of the ignition, for example an ignition coil failure so other possibilities should be ruled out. Problems with the ignition sparking are also a possibility. The engine may also cut out or be hard on starting. Problems with the engine cutting out or misfiring will most often occur when the engine has warmed up and the vehicle has been driven for some time. As with all ignition problems it is essential to get repairs completed as soon possible, as any untreated issues can cause the vehicle to cease operating.