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Alternator vs. Voltage Regulator

1991 Volvo 240 (245) wagon, California car with 140,00 miles. The "battery" symbol lit up dimly for several days until the engine began to perform erratically and the instrument panel became psychotic. Finally it failed to run at all, with a dead battery. At night of course. When I substituted another battery everything went back to normal, other than not charging, which I verified using a multimeter. Did not notice any odd sounds coming from the alternator area. From You Tube videos I learned that the built in voltage regulator may have failed, specifically the brushes.
Questions:
- Is this about the time/mileage to expect the voltage regulator and/or brushes to fail?
- Is there any other checking I should do?
- Is it reasonable to conclude that only the voltage regulator has failed?
- What is involved in removing and replacing the built in voltage regulator?
- Can it be done without removing the alternator?
- Any helpful hints on that job?
- Is there a way to coax a few more miles out of the alternator/voltage regulator?

I plan to order a new VR from FCP Euro ( (Voltage Regulator (80 AMP) - Bosch 30091 Part #: BOS-30091 $42) with lifetime warranty.
Any helpful advice will be appreciated.








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    Alternator vs. Voltage Regulator

    140K miles is about right for the brushes. The voltage regulator and brushes come as one unit that is removed from the back of the alternator with a screw driver. Make sure that you disconnect the positive battery cable before you replace the VR. Replacement should take about 10-15 minutes.

    The original Bosch alternators are very robust. It is not unusual for them to last 250,000 miles (with one or two VR/brush pack replacements). I would NOT replace the alternator in your car unless it needs it because even the remanufactured Bosch units are relative junk. You are lucky if a reman lasts 5 years.








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      Alternator vs. Voltage Regulator

      Thanks "OleSeaHorse" for alerting me to the possibility that the bolts may be corroded, and to "Charles Crawford" for valuable information. Apparently I missed your contribution when I first reviewed the responses. Thanks also to "pageda" for responding to my inquiry about removing the old regulator. Allow me to clarify. I was not clear with my question. It has been several weeks since this symptom occurred. have not gone beyond gathering information and ordering the part, which I now have. Just waiting for a time when I can set aside a couple of hours or an afternoon to tackle this task. Meanwhile, I have been charging up the car battery every couple of days. Recently, I notice that the battery will not take a further charge - the charger indicates that it is fully charged. This tells me that the regulator is back to work, hence my postponing this job as it is not urgent at this time. In addition, at night I no longer see the "battery" light glowing. I carry a spare battery and cables in the trunk. My question about removing the regulator was this: If I remove the regulator and for whatever reason I do not install the new one, will any damage be done by driving the car around with it out? I understand that the battery then can't possibly be charged. I can deal with that by charging the battery each day. Not ideal of course, but doable - I think. Possible reasons for not completing the job would be running out of time, running into an unforseen problem, or having something happen that doesn't allow the new one to go in readily. A couple of You Tube videos suggested there may be problems with this task. A further question would be - Is there any damage done by not having a working regulator even thought the battery is fully charged each day?
      Apparently I missed your contribution when I reviewed the responses. Thanks also to "pageda" for responding to my inquiry about removing the old regulator. Allow me to clarify. I was not clear with my question. It has been several weeks since this symptom occurred. have not gone beyond gathering information and ordering the part, which I now have. Just waiting for a time when I can set aside a couple of hours or an afternoon to tackle this task. Meanwhile, I have been charging up the car battery every couple of days. Recently, I notice that the battery will not take a further charge - the charger indicates that it is fully charged. This tells me that the regulator is back to work, hence my postponing this job as it is not urgent at this time. In addition, at night I no longer see the "battery" light glowing. I carry a spare battery and cables in the trunk. My question about removing the regulator was this: If I remove the regulator and for whatever reason I do not install the new one, will any damage be done by driving the car around with it out? I understand that the battery then can't possibly be charged. I can deal with that by charging the battery each day. Not ideal of course, but doable - I think. Possible reasons for not completing the job would be running out of time, running into an unforseen problem, or having something happen that doesn't allow the new one to go in readily. A couple of You Tube videos suggested there may be problems with this task. A further question would be - Is there any damage done by not having a working regulator even thought the battery is fully charged each day?








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    Alternator vs. Voltage Regulator

    Thank you 1owner122, CB, and alschnertz for your helpful and encouraging comments. I have purchased the new voltage regulator and am awaiting its arrival.
    Question: Is there any reason I cannot take out the old regulator and put in the new one at a later time? In other words, driving it with the old one out? I cannot imagine there is, but I feel better asking rather than assuming.
    Also, have you found it any easier to R & R the regulator by doing it from below?








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      Alternator vs. Voltage Regulator

      If you take the regulator out and drive the car the battery will quickly discharge and you won't be able to drive any more. It's also not good to completely discharge the battery.
      Dan








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    Alternator vs. Voltage Regulator

    Agree that it's likely the brushes which are a breeze to replace.

    Disconnect the neg. battery cable before performing the replacement to avoid shorting anything while you're doing the repair.








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    Alternator vs. Voltage Regulator

    You wrote:
    - Is this about the time/mileage to expect the voltage regulator and/or brushes to fail?

    It is about time that the Brushes are Worn down to nubs.

    The very first thing to do is to remove and inspect the BRUSHES --- Odds are they are so worn down that they no longer make contact with the slip rings ---Thus NO Charging.

    The Regulator/Brush unit can be removed without taking out the Alt. A Mirror will help you see the back of the alternator.
    2 screws or Nutheaded screws(use a nut driver or 1/4in drive ratched) hold in the Regulator/brush pack.

    Brushes can be replaced if you know how to solder and find the right size brushes.
    Otherwise just buy the whole unit - regulator/brush.

    You Also Wrote:
    - Is there a way to coax a few more miles out of the alternator/voltage regulator?

    NOT the Worn Down BRUSHES. The Voltage regular itself is probably OK.
    IF you find that the Brushes are Long and not worn down then there cud be other problems, but the Voltage Regulator itself is way down on the list.

    There shud be YouTubes showing how to do this on a Volvo 240 --- Try the IPD website. They have numerous How To Videos








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    Alternator vs. Voltage Regulator

    regulator is held in by 2 screws. easy access without removing alt.








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      Alternator vs. Voltage Regulator

      Two screws may be easy...or they may be miserably corroded. The Bosch uses slotted screws. Make sure your bit fits securely.
      For all those reading this post who own a NipponDenso alternator, the screws are "Phillips" style however the proper bit is a jis, Yes, Jis #2 not just any bit.

      Marty







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