Nissan Repair: Nissian Primera 1995, 1.6 alternator light, necessary voltage, car heater

Question
Dear Expert,

I have been having a weird problem with my car for at least 6 weeks now.

The alternator light (on the dashboard) started to go red while driving, and then going on and off all the time. It would stay red for 30 sec and then go off, and then it will go read again after a while. It will only start doing that after a drive 3-4 km.  

I have visited an electrician who suggested to change a part in the alternator and said it will fix the problem. Well it did not, but when doing checks on the car again he said that now the alternator was working perfectly fine giving the necessary voltage, even when everything in my car (heater, air conditioner, stereo, lights) was on. So he told me that he did not know what the problem was and that I should come back when it was evident what the problem was.  

To see whether it was an alternator or battery problem I unplugged the battery while the engine was running and everything was running well, the car would not die. I did the same thing when I have notices that the alternator light went red, and the engine kept on going but there was a weird vibration sound coming from the 3F105 block that has the Air Con, EGI, Fuel Pump, Rad Fan 2 reles (not sure about this word).

I hope you can help me out with this problem of mine. Thank you in advance.

Roman


Answer
Roman,

If the alternator light is coming on there is probably a diode going out in it.  There are three and it will charge the car with only two working.  I would check the charging system to see what the output is and if it is 14.2 volts your alternator is fine.  If this is the case check the wiring to make sure they have the wire for the charge light connected properly.  Also, there are fuses at the positive side of the battery cable and one could be fried.