Hey guys,

I have a 2005 mustang gt and I have seen a lot of posts on here about alternator issues with this model. Well for a long time now (going on 2 years) almost every time I get in the car and go for a ride about 5 minutes into the trip I get the "check charging system" alert on the dash. The light for the battery also comes on and then within the next 15 minutes the alert goes away and the battery light goes off.

I have taken it to ford and then said the alternator was faulty, but I chose not to replace it. Do you think they are just trying to get me to buy an alternator? I have had alternators go out in other cars and it's always been just a sudden thing , I find it odd that the alternator could be bad and has lasted so long

Your thoughts??

 

Could be something like a bad diode in the alternator.
Check the voltage at the battery with a volt meter. Also check the voltage from the B+ on the alternator and found at the battery. Let us know what you find

Probably a bad alternator.
Should be charging between about 13.4 and 14

 

It's most likely the alternator...you are correct in the fact that there is known issues with the alternators between 05-09.
Some of them just go out (like mine at 9:30pm on a back road) and other will flicker in and out, look like they are giving up then look fine.

 

I guess I've been lucky with my 06 gt, hasn't given a single problem yet.

AM sells a 'performance high output' alternator that cranks at 200 amps or watts i forget, or something, its pricey but I hear it fixes the problem.

autozone has a performance alternator that gives like 135...is that good enough guys? what is the stock amps or watts i forget?

 

if you are around 100k in mileage you are pushing you luck on the 6g ford alternator. The brushes and the slip ring are worn out. Ford made the brushes integral to the regulator and come as a unit. Ford has several brush holder/ regulators so you have to pay attention to the color of the regulator. Such as white body with blue cover. The other weak link is the slip ring that the brushes ride on. The copper rings are thin and wear uneven. They cannot be turned down like alternators from the past. The slip ring can be changed out but if it is the first time for the alternator it gets a little involved. Of course new bearings and tolerance ring should be replaced while rebuilding.
Don't rule out the pcm and cluster as they play a part in the charging system
This is only if you want rebuild it yourself if not just disregaurd

 

Honestly it wouldn't be a bad idea to buy a new alternator even if the one you have is still working for now. Be nice to know you don't have to worry about it going out at any time.

 

any idea if there is a thread on how to rebuild one? I have a 200 amp paperformance alternator that is showing 10.6 volts on the tester at a garage. Looking to rebuild it. Any help would be appreciated

 

Man this is an old thread... Guess I should have posted a long time ago that I ended up fixing the problem by replacing the alternator, haven't had a problem with that since.... Now if I could just figure out this stupid water leak...

 

I am curious as to why you bothered taking it to the dealership to diagnose and you didn't want to take their advise?

 

When I took it to ford I took it because I was having issues with my alarm going off randomly for no reason... Turned out to be a hood sensor, while it was there I asked what they thought and they said most likely the alternator, I just found it hard to believe I would have issues with the alternator for so long. When I replaced it I took it to auto zone and had the alternator tested a bunch of times and not once did it say it was bad