Avoid chain parts-store Alternators!!!

[imsolidstate]

I've read here about people having problems with remanufactured alternators from chain parts stores, but dismissed most of it as bad luck or bad diagnostics. But I am now a believer, and you should be too; here's why:

I have had a battery light flickering on and off in my truck for almost a year. It never got worse, and the truck started and ran just fine so I have been keeping an eye on it and saving some cash. A few nights ago, the truck was slow to start so I put a meter on the battery (engine running) and got 11 volts. Time to change that alternator! I had to drive to the next town because no one locally had an alternator (inluding Ford). I changed it the next night, and went for a test drive, but still got the battery light. I tested the system voltage, and it was still low so I figured that the batteries were probably going out too. (I have about 90k miles) So I drove to the parts store the next day, and bought two batteries. The truck died in the parking lot, so I ended up changing them in the parts store parking lot. Two new batteries, one new alternator, and I still drive home with a battery light.

So I get up the next morning, put a voltmeter on the battery, and an ammeter on the alternator output wire. I turn on the key, and check for B+ at the alternator. B+ is good. Start the truck, and battery voltage goes DOWN. From about 12.4V to 12V. Ammeter reads 0. I am now forced to believe that I got a bad alternator out of the box.

I called the parts house, had them keep my core, and went up there. They bench tested the alternator, and it failed. They pulled another one off the shelf, all the while with "we've had really great luck with Brand X alternators", tested it, and it failed too. So I went to Ford. Luckily, they got in a shipment and had one. It was 50% more expensive than the parts house, but it actually says motorcraft and the quality was significantly better. Believe me, I build automation equipment and design prototype systems for an aerospace company. The difference in quality was visibly apparent. The epoxy coating was actually coming off of the new parts house alternator and when you spun the pulley you could hear it crackling inside. The connections from the windings to the internal diodes were tenative, the pulley was some crappy steel that was about four times heavier than the stock one, and the rear half of the alternator was actually sitting crooked relative to the front half. The bolts that hold the core together were actually crooked and looked bent. By the way, it didn't work.

So, long story short, don't be like me and try to save money on a part that will leave you stranded if it doesn't work. Don't support these parts manufacturers that send their manufacturing processes to other countries to be made by the cheapest labor. Buy it from Ford because it really is better. And it works.

[HighwayPrisoner]

I agree about the parts store rebuilt junk, but that "genuine Motorcraft rebuilt stuff is not much better! That wonderful warranty 12 months or 12,000 miles is bs. I have been the Motorcraft rebuilt starter route, it was junk, not long after the 12K miles. I presently have a "genuine" Ford reman PCM fail in less than 30 days, but have 12,737 miles since the install. The verdict, out of warranty by 737 miles. They are sorry, but I have to pay for another PCM. The original PCM lasted 791,402 miles, and did not fail completely, like the reman PCM. The other bonus is an $80 tow bill, and three days downtime. Ford can keep their reman Junk!

[bugman]

Rebuilt parts are just that rebuilt. The question is what did they replace? Just what they showed bad or everything? The best luck that I have had is going to a local rebuild shop and either having them rebuild the one that I have or getting one that they have on the shelf. Even then you can run into the same problem but you have a local business that will help you out with it.

[pjwoolw]

The remanufactured stuff has really gone down hill. Or should I say worse. Anything electrical has been bad for many years. The Motorcraft brake parts that are rebuilt don't even look like what you took off. On my 97 the two front calipers are different castings. The rear brake cylinders were the same part number but look completely different. They are the same dimensionally and work fine but is is disconcerting. Plus you pay top dollar for them.

[poppie]

Originally Posted by HighwayPrisoner

I agree about the parts store rebuilt junk, but that "genuine Motorcraft rebuilt stuff is not much better! That wonderful warranty 12 months or 12,000 miles is bs. I have been the Motorcraft rebuilt starter route, it was junk, not long after the 12K miles. I presently have a "genuine" Ford reman PCM fail in less than 30 days, but have 12,737 miles since the install. The verdict, out of warranty by 737 miles. They are sorry, but I have to pay for another PCM. The original PCM lasted 791,402 miles, and did not fail completely, like the reman PCM. The other bonus is an $80 tow bill, and three days downtime. Ford can keep their reman Junk!

------------------Highway,good to hear from you,i guess with the downturn in RV sale's your not pounding the pavement as much as before,your post some time back about the item's you have replaced on your truck,i think you said you got 120,000 mile's out of the factory tran's and then got a suncoast that ran l something like 250,000 mile's or so,then you went to the BTS,is that the original BTS or has it been replaced???,for the people reading this post keep in mind,Highway's truck is his bread and butter and work's almost non stop unlike some of the daily driver's on here that run empty most of their life,let us know when you cross the million mile mark highway,there's not a 6.Oh Oh or 6.4 that will ever see that kind of service you have out of that 7.3,dang EPA.

[LiftedBlackHD]

i just ordered a new, made in America large case, 6G, 140 amp alternator from alternatorpartsdot com. This is an upgrade over the factory unit. It was $189 and you get to keep your original. It should be here in a few days...

[yanvaryjt]

I just changed my alt yesterday morning - last one went out at 50k miles and this time 89k miles. The last time, I picked up an alt from the local parts store with the 12 month warranty. It lasted 18 months. This time I paid a little extra for the lifetime warranty - at least it's replacement will be free when it sh!ts the bed next year.

[imsolidstate]

LiftedBlack HD - that sounds like a killer deal. Let me know how happy you are with it, and if it lives up to the specs. I wanted the higher amperage alternator, but I needed my truck running so I took what I could get.

Just out of curiosity, has anyone ever measured the draw on their alternator to see how much current is really being drawn by the truck's electrical system? I only have an AC current clamp, and a DC current clamp is probably not going to be very accurate since there should be a pretty good ripple on top of the DC.

Maybe if anyone else is as curious as I am about this data I will find a way to measure it. I have been thinking about using the resistance of the alternator output wire as a current sense resistor, and measuring the voltage drop with a differential amplifier and an oscilloscope to measure the current that passes down the wire.

Maybe I'm just wasting my time, but I would like to know how close my truck and trailer with the lights on and trailer brakes gets to the stock 110 Amp alternator rating.

[acausey]

I was also wondering what the current draw should be. I would imagine a good DC current clamp should have enough averaging built in that it would get you pretty close. I may be able to borrow one to check my truck. I'll post what I find...

Andy