Alt Voltage

Could one of you WRX people check out your voltage at idle. I thought it was just my battery that went because I could run fine, and when I went home after changing it I was reading 13.5-14V, but now I was idling in my work parking lot and it was 12.3V This seems a little odd to me, I am used to voltage while running never realy being below 13V, and I am suspecting the voltage regulator, or the alt itself.

 

chances are, its the alt, turn everything on, then to a voltage check if its super low its your alt almost for sure

 

I could help you double check it with another tool at Firestone if you would like just to see if you get consistent results from your alternator voltage.

 

I used 2 sepperate meters, and it was even worse last night. Since it is a warrenty part I took the car over to Morries... Talking about that I should give them a call some time. thanks for looking.

 

well intresting thing. This is being a PITA....The alt performed perfect doing a alt test. (14V at 60 amps or something like that). Battery is good, and also tested.

I have the amps completely unpluged now. Could some one check theirs to see how constant their voltage is at idle, and idle max ac, and while on the freeway. idle would be a great start.

When AC is on at idle 12.2V but freeway speeds it is between 12.8 and 13.4V
with everything off it is 13.4-14V on the freeway, and 12.6-13.1 at low idle.

The way this is reacting it doesn't make sense.

 

From what you describe it sounds fine to me. If it was the regulator you'd be spiking way above 14v as you reved up the engine.

 

Yeah it isn't spiking high, it just seems weird to me that it gets to 12.2. with the AC on.... I checked my durango. 13.4 at idle, 13.6 at free way.... but constant. I wonder if I was checking the "powered" port and if that has a voltage regulator to keep it high. I just don't think that I have had a car that didn't read 13+ all the time.

 

So I replaced the ALT this weekend and everything is fine now. What it seems to me is that Mories chared up the battery fully before they tested and didn't relize that it was just slowly discharging the battery. I belive it is just one of the phases of the alt that went out, so it produced roughly the same voltage, but never the same current. I am getting the alt tested by a parts store soon. This is exactly what I suspected was wronge and told them, that they miss diagnosed. Anyways this kind of makes me feel uncomportable with them now to.