Alternator out?

[Brewster]

Alternator went out tonight about 3 miles from the house. First thing I noticed while driving down the road was my ABS and TCS lights came on...then slowly my dash, and headlights faded out. The car kept running so I stopped at Autozone and they said the Alternator was only putting out 8 volts. Drove home without light and shut it off. Tried to restart...battery was dead....so It's on the charger now and taking a charge.

For those of us with an 05 to 09 Mustang...If you had to replace your alternator, how long did it last you? My car is an 07 Mustang GT with 47k miles on it. Is this normal life expectancy? Wondering if anything else could be causing this same effect as well instead of the alternator. I recently installed a TVS Phase 1 Supercharger kit (2 weeks ago) and had to cut off a couple of the alternator's "ears" (mounting points) to re-install it with the TVS. I taped up the alternator pretty good to prevent any of the metal dust from getting into the it during the surgery but I wonder if some could've gotten in there and cause the alt to fail prematurely. I'd think if that was the case it would've failed in the first day or two after the TVS install but it's been doing fine for a couple of weeks post S/C install. Maybe it's just coincidence and it's time for a new one.

 

[toorbeenee]

05-09 are known for bad altenator

 

[Ingwe]

Just had the same thing happen to mine on an 08 GT/CS with 30,000miles on the clock. Exact same symptoms and i know of 2 other cars that have similar age/mileage and the same problem in the last 4 weeks. I doubt your S/C would have been the problem.

 

[bigray327]

It's amazing how many alternator threads we get here. Alternators are the new "what color stripes should I get?"

 

[ProStang01]

My battery light and check charging system indicator just came on Saturday night. Battery reads close to 12 volts and alternator reads close to 14 volts. Debating if I should change the alternator. Not easy due to blower and all the piping.

 

[ProStang01]

I take that back, it's located under throttle body. Just blower pipes need to be moved..

 

[psycho bob]

For those of us with an 05 to 09 Mustang...If you had to replace your alternator, how long did it last you? My car is an 07 Mustang GT with 47k miles on it.

this is almost exactly the same as mine. my 07 just went out on my wife and it has around 46-47k on the clock also

 

[Newman]

Mine went a year ago with same symptoms at 62K

 

[rford426]

Just put a new one in mine last week im at 58k

 

[bradleyem]

The only thing that adding a s/c may do is reduce the life of the alternator because of heat. With some s/c installations, the alternator spins bacward. This has no effect on the alternator output, but the cooling fins spin the wrong direction, decreasing their ability to cool the alternator. Plus many superchargers cover and bury the alternator even more than it already is, and they add more heat to boot. So it's a recipe for failure for the alternator, but not really anything that you can do about it...

Sent from my DROIDX using Tapatalk

 

[nightrain]

I cant believe how many of these cars are having the same issue?? mine did the exact same thing last saturday, its an 08 with 40k on it im replacing mine today

 

[RRRoamer]

My battery light and check charging system indicator just came on Saturday night. Battery reads close to 12 volts and alternator reads close to 14 volts. Debating if I should change the alternator. Not easy due to blower and all the piping.

Let me see if I am understanding this statement correctly. You say "Battery reads close to 12V" meaning with or WITHOUT the engine running???? If that is with the engine off, then maybe a bit low, but nothing to scream about probably.

Then, you say "and alternator reads close to 14 volts". Ok, the only way to measure the output of the alternator is with the engine running.... So does this imply that you measured the batter voltage at the BATTERY with the engine running and the when you measured the voltage AT THE ALTERNATOR (again, with the engine running) you got 14V?

If that 12 volts is at the battery with the engine running but you are getting 14 volts at the alternator, then you need to go over every inch of the cable between the alternator and the battery because something is jacked up there. The alternator cable is a very low impedance connection to the battery, so the alternator and the battery should always read just about exactly the same voltage at any given time.

 

[ProStang01]

Let me see if I am understanding this statement correctly. You say "Battery reads close to 12V" meaning with or WITHOUT the engine running???? If that is with the engine off, then maybe a bit low, but nothing to scream about probably.

Then, you say "and alternator reads close to 14 volts". Ok, the only way to measure the output of the alternator is with the engine running.... So does this imply that you measured the batter voltage at the BATTERY with the engine running and the when you measured the voltage AT THE ALTERNATOR (again, with the engine running) you got 14V?

If that 12 volts is at the battery with the engine running but you are getting 14 volts at the alternator, then you need to go over every inch of the cable between the alternator and the battery because something is jacked up there. The alternator cable is a very low impedance connection to the battery, so the alternator and the battery should always read just about exactly the same voltage at any given time.

Yes it read 12 volts with engine off. And then read 14 volts with engine running. I was told the 14 volts is too high...

This was all done with a battery/alternator load tester.

I ordered and swapped out my alternator today on my lunch break and it fixed the problem. I hope that was the right thing to do because it cost me $300 bucks!!

 

[SeVeReDiStOrTiOn]

Anyone know why the PA performance alt comes with a regular pulley and not a clutch pulley? I hear good things about the PA from you guys but the tuff stuff alt summit sells is looking good too...it comes with the clutch pulley and is powder coated black.

 

[Sprayin Blue 3V]

Yes it read 12 volts with engine off. And then read 14 volts with engine running. I was told the 14 volts is too high...

This was all done with a battery/alternator load tester.

I ordered and swapped out my alternator today on my lunch break and it fixed the problem. I hope that was the right thing to do because it cost me $300 bucks!!

14 volts is not too high. Mine just read 13.8v. How do u expect it to charge if there isn't more than 12v?

Just because it works fine after u replaced it doesn't mean that fixed the problem. Seems like there is an issue elsewhere. Check things like belt tension and check to make sure the fan is working right.

 

[silverstangz]

had the same problem, got the pa from AM and fixed !!!!! just sayin.

 

[ProStang01]

14 volts is not too high. Mine just read 13.8v. How do u expect it to charge if there isn't more than 12v?

Just because it works fine after u replaced it doesn't mean that fixed the problem. Seems like there is an issue elsewhere. Check things like belt tension and check to make sure the fan is working right.

Sprayin I'm just going off what I was told. But I think you may be right. Damn thing got me stranded last night. Before I made it home last night it died on me... Soon as I get it back here I'll have the alternator tested and then go from there.

How do I go about checking the tensioner??

Brewster didn't me to highjack your thread!

 

[ross0616]

Mine went out at 37000 miles right after my warranty was up go figure. Stranded me in SC on Christmas eve about 2 years ago.

 

[G Wrecks]

When your car is running, your battery is supposed to put out 14.4 volts. I have no clue how many volts the alternator is supposed to put out, but I'd assume 14.4 volts as well.

Obviously the battery is supposed to produce 12 volts when the car isn't running.

 

[RedfireV8]

Just giving my quick story of my alternator mishap"s". Went through 5 of em in 2010. The longest one lasted was 3 months and the shortest one lasted was 2 weeks. On my 5th one, I went ahead and removed the HID's and problem fixed. (Yes they were hooked up correctly.) Never had another issue. All replaced under that nice $1800 warranty I bought with it. BTW, its $550 just for an alternator replacement from your local, wonderful dealership if out of pocket.