Results 1 to 7 of 7

Thread: Alternator exciter reluctant to activate

  1. #1

    Alternator exciter reluctant to activate

    Iím having an issue where my alternator is not charging when the car is started until the motor revs over 2,000rpm. This is the second alternator and the first had the same issue although it needed to get 3,000+rpm before charging. The first alternator stopped working entirely after about 1,500 miles. Both are new Valeo alternators.

    The alternator light comes on at start up and does not go out until I blip the throttle to the previously mentioned 2,000rpm. I have confirmed this with a multi-meter as well. Iím thinking it might be the exciter circuit in the voltage regulator but what are the odds of two new alternators having the same issue?

    Any help would be appreciated.

  2. #2
    Senior Member
    Join Date
    Apr 2004
    Location
    35,000 ft
    Posts
    1,998
    I found this useful when tracking down similar issues.

    If you’ve got a lower wattage bulb, or (god forbid) LED indicator lamp. Or swapped to an alternator with a built in regulator, the factory recommended a resistor be placed inline with the lamp on the dashboard. 91ohm and 5 watts. Or just use a 5 or 6 watt bulb

    https://forums.pelicanparts.com/pors...tor-light.html
    looking for 1972 911t motor XR584, S/N 6121622

  3. #3
    Thanks. My kingdom for a Radio Shack!

  4. #4
    Mike, sent you a PM.

  5. #5
    Senior Member
    Join Date
    Oct 2008
    Location
    Burford, ON, Canada
    Posts
    4,229
    Exactly what alternator bulb are you using? As mentioned, an LED bulb CANNOT be used in this application.
    Porsche Historian, contact for Kardex & CoA-type Reports
    Addicted since 1975, ESR mbr# 2200 to 2024 03
    Researching Paint codes and Engine Build numbers

  6. #6
    Thanks Rick, and Dave it's a standard bulb. I even swapped it with another in the cluster to see if there was a problem with that particular one.

  7. #7
    Thanks to Blucille and Rick the problem has finally been solved.

    Name:  IMG_0322.jpeg
Views: 79
Size:  104.0 KB

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Message Board Disclaimer and Terms of Use
This is a public forum. Messages posted here can be viewed by the public. The Early 911S Registry is not responsible for messages posted in its online forums, and any message will express the views of the author and not the Early 911S Registry. Use of online forums shall constitute the agreement of the user not to post anything of religious or political content, false and defamatory, inaccurate, abusive, vulgar, hateful, harassing, obscene, profane, sexually oriented, threatening, invasive of a person's privacy, or otherwise to violate the law and the further agreement of the user to be solely responsible for and hold the Early 911S Registry harmless in the event of any claim based on their message. Any viewer who finds a message objectionable should contact us immediately by email. The Early 911S Registry has the ability to remove objectionable messages and we will make every effort to do so, within a reasonable time frame, if we determine that removal is necessary.