Relay Switch



I am an amateur. My dad and I tried our hand at replacing the alternator in my '94 nissan sentra. The car runs, but only off the battery. Is there a switch of some sort we should have reset and where is it?


There is no reset switch in this circuit. It sounds like you have removed a battery cable while the engine was running and then it died. You should not do this.

Make sure the red Battery light on the dash illuminates when the key is on. This light MUST work for the alternator to charge.
Also, you should check the fusible links near the battery. There are 2 in the circuit and if one or both are blown the alt. will not charge the battery or keep the engine running.


No, there is no on/off switch for a car’s alternator. My guess is that you failed to make a connection somewhere, possibly the alternator plug to the main wiring harness. You might also have a bad battery ground-chassis connection.