Hello,
I currently am driving a 2001 F-350 V10 SuperDuty, and recently the battery light was blinking. I replaced the alternator in it, but it didn't work. I thought it was bad so I went and got another and it still didn't work. Turned out that the alternator wasn't big enough. I then went BACK and got a larger alternator, and it still won't work. Now the battery light is solid, and i'm getting absolutely no charge out of the alternator. I checked all the fuses and nothing is wrong. It seems like all the things you think could be wrong are running perfectly fine!

I was wondering if anyone could give me some sort of idea as to what could be wrong. The truck will start, and idle, but will run off the battery only.

Thanks,
Kirsten.

 

I bought rebuild alternator from NAPA few months ago and it was blinking red light from day 2. The blinking become more and more often, but alternator passed the bench test with flying colors. Finally it gave up and now I drive happy with alternator from Kragen.
This is short story as I don't want to use adult language here.
Bottom line -the power regulator is build into the alternator. Meaning as long as you have the wires correctly connected to the alternator and there is no charging -the alternator is bad. End of the story.

 

You may want to check your wire connection between the battery and the thick wire on the alternator. Also, check the wires on the battery. Clean corrosion off the terminals.

The wire harness on the back is the wires to the voltage regulator. Make sure that is connected good.

If you have a multi-meter, check the voltage off the big wire on the alternator while engine is running. It should be 13.5V-14V. Then check voltage on your battery. It should be the same give and take 0.1V. If it is around 12V, then you have a bad connection between the battery and alternator.

Good luck.

 

Don't over think this. The alternator makes power. The cables transmit it. The battery stores it. If your battery and cables are good, then the alternator is the problem.

 

All you really need to do is go to napa or autozone and take the truck there. They can test your charging system at the vehicle. Don't shoot in the dark anymore.

Its free too.

 

Consumers wanting lower and lower prices lead to almost all alternator and starter rebuilding to be outsourced to Mexico or other ultra-low cost labor countries. I've been in one of those "rebuild" shops. Let's just say it is not what you think it is....

My experience: 75+% of these rebuilds fail within 6 months if they work at all.

If you need a reliable solution, take the ORIGINAL to a local rebuilder who knows what they're doing, or buy a brand new one. Or hunt and hunt to find a retailer that buys rebuilds from shops that still use skilled labor and new parts. Good luck on that.

 

We heard from many sources that the alternator brand is bad, we have had 3 tested and they were all bad. It just seems unreal that we had this much bad luck with them.. The bran is USA Industries, or something.

We're going to try a different brand this time, but thank you all for your help. I really appreciate it.

 

In my experience, all the "chain" parts stores are now selling crap. Inexpensive, but who can afford it when it doesn't work?
I'd rather pay a fair price for something that works and lasts....
Suggestions:

The last time I talked to these guys, they were still rebuilding them with skilled labor and new parts:
Car Alternator Prices - Cheap Alternators for Sale - Alternator Replacement

And for the ultimate:
6G Series Heavy Duty Bridge Rectifier High Output Alternator
I'm using a 160A with extra external rectifier from them. So far, excellent.

 

I have a local shop here nearby that rebuilds alternators and starters. I got a Motocraft rebuild alt. for $100 ($150-$50 core). 2 years now and so far so good.

I would check a junk yard if you want OEM. They typically give you a 30 day warranty.

 

went to autozone they told me alternater was bad, bought a another one, (4th) just started it and battery light is on dim, but on and still not charging. checked all connections ,all grounds still not charging! Stumped

 

Then you probably have a 4th bad alternator.

 

I was playing with voltage readings when my alternator was acting and noticed that the regulators will not start charging till several seconds after the engine start up. So make sure you give it some time before coming to a conclusion.

 

We did try this. We had it running for a minimum of 10 minutes earlier and there was NOTHING. The readings on the battery just kept slowly decreasing.

 

What's the voltage at the alternator while it's running?

Return the one back to Autozone and exchange it for a new one. Have them test the new one BEFORE you leave.

 

The issue with the alternator not putting voltage out is not an issue of the alternator being bad. Had an issue just like you mentioned and replaced the alternator. Took the old one in to get the core back and had it tested. Figures it tested fine. In crawling around the internet for a solution I learned about the orange wire with light blue stripe in the alternator plug. It tested good with voltage but when I tapped onto it with a jumper and touch it to the battery positive terminal the alternator starts generating power. You hear the engine rpm drop and the voltage jumps right up. The wire runs back to the fender with the large yellow wire from the alternator. They have fuseable links in the harness. According to ford techs this not uncommon. Would be nice if yiu could buy a replacement alternator harness.