Crap Alternators, or....?

Electrical & Ignition

  1. beanhead

    beanhead Well-Known Member

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    I've had two alternators, NAPA replacements, fail in the course of the last two months. Got 6 weeks out of the first one, 2 weeks (probably 50 miles) out of the second one. What happened is, they worked just fine, and then out of the blue upon startup I noticed the ammeter needle over on "discharge". Both times they showed low voltages during idle (11-12v) and no change with a full-field test.
    Install new alternator, all good...14.1-14.5v.
    It's a '68 RB running factory-style electronic ignition, battery is fine, solid-state regulator. The wiring is in good condition, grounds and connections are healthy. Everything works just fine until the alternators decide to stop putting out.
    Now, I keep going back and getting my free replacement, and this last time I made them give me a different model...but I'm curious if there could be some underlying condition that's burning these things out after a bit of use. The previous units definitely failed, but why?
    Or were they simply junk re-mans?
    I'm prepared to accept that they were just poor quality, but if there's something I should test or look at that I might be missing, I'm open to suggestions...
    Thanks
     
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    • Kern Dog

      Kern Dog FBBO Gold Member FBBO Gold Member

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      I have heard of some troubles with some of the NAPA replacement parts lately.
      A buddy in the car club had TWO water pumps blow apart and take out the radiator each time....2003 Hemi truck.
      I used to think that they were a premium quality parts store but maybe they have had to cheapen their product line to compete with the Auto Zone and O'Rielleys crowd?
       
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      • beanhead

        beanhead Well-Known Member

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        Yeah....I probably just got a bad run, I'm sure from the same assembly line. This last time they gave me a higher-amperage 70s unit, maybe the third time will be a charm!
         
      • Curiousyellow71

        Curiousyellow71 Well-Known Member

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        Fumny to read this..Napa apparently is going through some part quality issues. On my 6.7 cummins I got a month out of the first water pump from napa. They exchanged it, I got 3 weeks out of the one they exchanged. They were new...Its not hard to replace on a cummins compared to a hemi, but I went to carquest for the third one this last weekend..crossing my fingers...I don't want to install another one...nor do I want to see the temp gauge at 250 for a few more years and ruin a engine on a crappy part. The napa water pump was 80 bucks from napa and both looked like they were made by two different companies.
        We take our alternators and starters to a shop a hour away that rebuilds them. It's a pain and we can't always wait...but the outcome is better. The last ten years new parts have been hit n miss. I thought napa "was" better:soapbox:.
        The guy at Napa said they are changing some parts to compete with other stores...
         
        Last edited: Sep 14, 2021
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        • dan juhasz

          dan juhasz FBBO Gold Member FBBO Gold Member

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          It is best to buy original equipment whenever possible. The higher cost initially is easily offset by the quality. Most aftermarket water pumps are cheap Chinese imports, ie Gates, Airtex etc.
           
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          • blue69runner

            blue69runner Well-Known Member

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            Got three alternators form O Rallies where the wrong amp alt. Wanted the lower amp so not too over power my system. Finally got it from classic Industries. Been working fine for now. Many years ago was getting starters and water pumps from like Discount Auto. But had problems with them. Went to NAPA and never had a problem again. Sorry to here your getting bad rebuilt product's. Life time warrantee dose not cover taking it off and returning the piece and putting it back on. That is what pissed me off. I only want to do it once. Just a thought make sure the shell of the alt. is grounded good.
             
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            • Don Frelier

              Don Frelier FBBO Gold Member FBBO Gold Member

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              I tell everyone this:
              “You Can’t Get Anything Good These Days”
               
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              • Ronnman

                Ronnman Well-Known Member

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                Yeah, there are issues with NAPA rebuilt alternators. I had a buddy who is a long time NAPA employee order 3 alternators for me to try and get one. All three were bad. We checked them at the counter and they all made noise when rotated, and one would bind and not make one revolution. He told me the rebuilt Chrysler alternators for NAPA were junk. I bought a new Powermaster alternator and haven’t looked back.
                Ron
                 
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                • Bee1971

                  Bee1971 Well-Known Member

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                  Same here , Brand New , no more rebuilts for me

                  Anybody want to talk Canister Oil Filled Ignition Coils

                  I didnt think so - Junk
                   
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                  • 69a100

                    69a100 Well-Known Member

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                    So, even blow jobs are out of the question now?
                     
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                    • ckessel

                      ckessel Well-Known Member

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                      Parts store remans blow and have been that way for many years. Using the "lifetime" or "free" replacement as their selling point is what catches most customers. Whats left out is your labor is not part of that. If a component wipes out something else, from being faulty, all they generally take care of is what they sold you. If you want to go to battle with them, you "might" get the rest of the calamity taken care of but don't hold your breath. Since price is the biggest driver of the reman and not quality, the minimum amount of parts get replaced so they can kick it out the door to the buying company. If they can get away with one brush, bushing etc, thats all that gets replaced. The only quality reman I've been around, 30+ years in parts, are the factory reman from Mopar, GM, Toyota etc. The factory has a lot more riding on the component as, if it gets replaced at the dealer, they are on the hook for towing/car rental/labor etc. For our cars, I'm not sure if you can get factory reman electrical anymore so you most likely will need to track down a rebuilder in the area that does a proper job or get new from Powermaster etc.
                       
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                      • 69Bee

                        69Bee FBBO Gold Member FBBO Gold Member

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                        The alternator will only provide the amount of current that the load demands, not more. A 1000A power source will only supply 10A to a 10A load and no more.
                         
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                        • RJRENTON

                          RJRENTON FBBO Gold Member FBBO Gold Member

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                          A curiosity question.....what failed in the first unit and later the second unit? It would be helpful to know exactly what component was the offender? Was the first alternator a round back, square back alternator or s Leece Neville design. If I were to guess, i would have to say a diode failure, in the square back design the most common failure was a negative diode. It is highly unlikely that either the stator windings or rotor windings failed.....I've only seen one stator failure as manifested as a large melted copper lump where the winding contacted ground. I've not seen a rotor winding failure. Many bearing failures, specific to the drive end bearing, is usually due to extremely high belt tension. Brushes and brush holders often cause erratic voltages produced. Diodes are subject to overloads, both current and voltage, transients caused by operator errors....incorrect connections, or jumping another vehicle....wrong polarity or loose output connections. If it were me, I'd want to know the mechanism of failure to determine why....but this is just me......sort of reverse engineering to determine the cause.....please advise if you can ......
                          BOB RENTON
                           
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                          • hyde-park

                            hyde-park Well-Known Member

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                            I had three failures from O'Reilly's over the course of two years for a twin pulley, 65 amp square back unit. After the third one the manager said this was the last free replacement I'd be given. A year later I still had to have it repaired on two separate occasions by a local gent who fixes alts and starters. The last straw came very recently when it started making bearing noise. I took my chances and got one from Advance Auto. It's only been a week and I don't drive the car much so we'll see how this one performs. In the 40 years since I played with cars, I've never had a new/rebuilt component fail this often in such a short amount of time. On the plus side I can R&R the thing a little faster each time, lol.
                             
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                            • RJRENTON

                              RJRENTON FBBO Gold Member FBBO Gold Member

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                              Again, out of curiosity, what failed in the first 3 units you noted?....rather than "it quit charging". They must be disassembled to make a determination....alternators are simple devices and all components are readily available for DIY fixes, rather than relying on someone else skills (?) or ability or some rebuilding company....as witnessed by your 3 failures. Can't offer any fixes if we don't know whats broke.......
                              BOB RENTON
                               
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                              • hyde-park

                                hyde-park Well-Known Member

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                                I don't know what the first three failures were other than they/it wouldn't charge anymore. I was not left stranded or had to have a jump or call for a tow. I pay attention to what my car sounds and at acts like all the time. If anything is amiss I notice it right off. In these instances it was the alt gauge reading (voltmeter conversion). I then backed up that finding at the battery with a simple handheld analog voltmeter. Then I got out the factory service manual and went thru the flow chart and testing procedures. Is there battery voltage here at this wire? Etc., etc. In the end I ruled out the voltage regulator but also tested with a known good spare. Performing a full field test of the alt did not produce any voltage. Okay that tells me it's most likely the alt. They tested it in the store with the same results and ordered me a another one. Got it a day or two later and off I went. If I'm paying for a warranted unit and it fails I don't care what was wrong with it. I'm not the one fixing it, just get me a replacement please. I assume my failed units were cycled back into their system for repair and resale. The two next failures were pretty much identical as was my testing. The two failures I had (after the warranty was voided) that I had fixed locally were these: Diode failure of some kind, don't remember what specifically. Then an internal short (grounding) full fielding of the unit which showed as 15+ volts being registered. When the bearing noise became evident I had enough of this particular unit and wanted nothing else to do with it. I simply shopped for one elsewhere. The telling of my story isn't meant as bash of O'Reillys. I still buy parts/supplies from there, just not exclusively as I once did.
                                 
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                                • beanhead

                                  beanhead Well-Known Member

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                                  Both square back-style, with one field terminal grounded for use with my early-style wiring. Mechanically they were fine, no noise or rough turning so my guess was also diodes..but it was just a guess, for as much as I wanted to tear into them for deeper testing, once they flunked the full-field test I simply returned them. I didn't want to give the store any reason to not honor the replacement....."oh we have to charge you because this screw's been removed..." you never know with these people.
                                  I have verified good connections, the wiring is good (1-1/2 yrs old), no jump-starts or funny business...Voltage never goes over 14.5 even on startup after sitting, so there doesn't appear to be an overcharge condition.
                                  I'm watching the third one closely...
                                   
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                                  • hyde-park

                                    hyde-park Well-Known Member

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                                    THIS QUOTE..."Once they flunked the full-field test I simply returned them. I didn't want to give the store any reason to not honor the replacement....."oh we have to charge you because this screw's been removed..." EXACTLY
                                     
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                                    • RJRENTON

                                      RJRENTON FBBO Gold Member FBBO Gold Member

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                                      I can appreciate your predicament.....yes, it is likely that, if any screw was out of place would void the "warranty" making you the villain. As long as you keep getting free units....WTF...why not. Perhaps i should have been specific to out of warranty units. I've "converted", numbers matching oem 37 amp units to 60 amp units, by simply changing the stator assembly and the diodes to the high current unit parts ...And ABSOLUTELY no one can tell the difference. As i mentioned, alternators are simple devices....if you can change a cam or replace a clutch or rebuild an engine you can fix an alternator or carburetor. But you must feel comfortable with what you can handle......and accomplish. Just my opinion of course....
                                      BOB RENTON
                                       
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                                      • hyde-park

                                        hyde-park Well-Known Member

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                                        Not so much as, "feel comfortable with what you can handle", as I don't want to do it. Maybe I'm lazy. Example: master cylinders are also simple devices. They can be rebuilt easily. Kits and tools to do so are readily available. I replaced mine last year with a remanufactured one. Just wasn't going to muck about with cleaning, honing, and whatnot to rebuild mine.
                                         
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