Does it read 14 volts even when the alternator light is on? I've had that happen on another car. Entertaining problem, traced to a diode whose role I never quite understood. Don't know how similar the 8's alternator is, but this could be past the DIY stage.

Does your new alternator have a warranty? If it was replaced at a dealer or a shop that backs up their work I'd suggest going back there.

Ken

 

Yes, even with the light on it reads over 14v..... Just so u know a diode serves as a blocking device for the ground signal. If u put It on a cable it will allow the signal to from "left to right" but it woll block the signal when it tries to travel from "right to left" depending there the arrow is pointing to....

I got the alternator from advance auto parts with a life time warranty so I guess ill take it back

 

Has the battery been load tested and verified good? It could be a diode as Ken has suggested but if the battery checks out, I would check the belt tension.

Diodes convert the alternator's A/C current to D/C current which is needed to run the accesories and charge the battery.

 

I started to have the alternator dash light coming on when turning on the engine. After driving about 4-5 miles on the freeway, the light goes off and it stays off for the whole remainder of the drive. Interestingly, it seems to relate to the temperature how soon the light turns off. When the car was parked on the sun (like at work during the day), it turns off quicker.

I wonder whether the alternator is on the way out or perhaps something else is at fault, since the light goes off all the time after some driving... also, there seems to be no other symptom, even when the light is on in the beginning, everything is normal, no dips or fluctuations of idle speed, nothing obvious is wrong.
Strange...

 

Update: I decided to replace the alternator after I measured about 11.8 V at the battery terminals when engine is cold and idling. Strange thing is that when fully warmed up and the dash light was off, I got 13.85 V, so at that point, the alternator appeared to work correctly. Still, seems like it was probably going to die on me, so rather than risking it, replacement was the way to get rid of the dash light. Now I'm getting 14 V when cold and idling, so everything seems the be OK so far.

Question: what can be done with the old alternator, other than tossing it? I got the replacement on with no core charge. Is it worth getting this rebuilt and keep it as a spare or sell it? If yes, what shops do usually rebuild these things?
Thanks.

 

I am having this same problem. I have replaced the alternator and the battery. They both test good but The charging light still Comes on intermittently. The battery is slowly draining. Under load the light goes off.

 

Time for a new alternator belt?

Is the old one cracked and shiny?