Alternator light stays on !

Discussion in 'Sparky's corner' started by Rivman, May 18, 2007.

  1. Rivman

    Rivman Senior Ottawa Buick Guy

    Great way to start the 2007 season - alt light stays lit, and engine dies when the battery is disconnected. Might be time for a new alternator? - thinking of converting to one with a built in regulator. Any tips, or specific instructions on doing the conversion in a '68 Riv ? I know I've read, or seen specifics on it somewhere, but eye can't remember where (. . . it happens when you get old !).
    Thanks guys 'n gals :Do No: :beer :TU:
     
  2. jamyers

    jamyers 2 gallons of fun

  3. 12lives

    12lives Control the controllable, let the rest go

    Randy -

    There is a real easy test but you have to be very careful...

    Disconnect the small plug at the back of the alternator. This is the plug to the brush assembly. Find the "F" or field terminal on the alternator.

    Put your test leads from your voltmeter on the battery to measure the battery voltage. You should read about 12v. Leave them connected.

    Connect another lead from the positive side of the battery. Use another test lead if you have one. You can use any wire, but you need a small pin connector at the end for the next step. (Keep the free end from touching anything)

    Start the car.

    Touch the free end of the test lead connected to the plus side of the battery to the F terminal on the alternator. This will apply a full 12 v to the field coil. On the voltmeter, you should see the voltage on the battery immediately start going up as the alternator starts to charge the battery. This is the careful part as it it not easy to do, especially if you have AC....

    As soon as you see the voltage going up, remove the lead from the F terminal. You can do it again to verify, but don't keep the lead on too long as the voltage will keep going up. Try not to touch anything else.

    This will tell you if the alternator is working.

    Also, with the engine off, you can touch the same test lead to the R terminal on the plug to the regulator and hear the ignition coil in the regulator click. This will tell you if thats working. Don't try this if the regulator is solid state....

    Reconnect the plug to the alternator and you are done.

    - Bill
     
  4. Rivman

    Rivman Senior Ottawa Buick Guy

    Thanks ! James - that's the info I remember, . . . and for the test info Bill, I'll check it out ! :beer :TU:
     
    Last edited: May 18, 2007
  5. Truzi

    Truzi Perpetual Student

    You know that you can't be sure it's a bad alternator unless you take it for a 100-mile round trip. If you make it home, the alternator is good. :)

    The conversion is easy if you follow the threads posted above.
     
  6. Rivman

    Rivman Senior Ottawa Buick Guy

    . . . or you got one great big mother energizer bunny under the hood ! :TU:
     
  7. BadBrad

    BadBrad Got 4-speed?

  8. Rivman

    Rivman Senior Ottawa Buick Guy

    Thanks ! Brad - some excellent info in those links ! :beer :TU:
     
  9. Howrad

    Howrad idiot... SAVANT!

  10. Rivman

    Rivman Senior Ottawa Buick Guy

    Thanks ! Howrad, looks like an easy, uncomplcated procedure ! :beer :TU:
     
  11. 65specialconver

    65specialconver kennedy-bell MIA

  12. Rivman

    Rivman Senior Ottawa Buick Guy

    Pretty shade of Green - Jamie is that wiring kit for a single wire conversion ? ( I want to retain the original alt lamp.)
    . . . kinda like the idea of not having to bastardize the existing harness ! :TU:
     
  13. 65specialconver

    65specialconver kennedy-bell MIA

    not a 1 wire,its for the 10dn to 10 si conversion,yes it retains the idiot light function.plug it in,stuff the reg harness in the fender so you dont see it.add the plug at the back of the alt & go!!pm me if you want one:laugh:
     
  14. jamyers

    jamyers 2 gallons of fun

    GREAT IDEA, Jamie! After staring at the GM wiring diagrams for both alternators, I ended up making my own little jumpers and doing that same thing on mine (without the nice alternator pigtail adapter - I cut/spliced a new one in). Wish I'd have known about your doo-hickey a year or so ago... :Dou:

    My memory may well be faulty, but iirc on mine I jumped the two outers together, and then the two inners together, unlike yours. Did they vary by year / model? (I'll doublecheck mine tonight).
     
  15. 65specialconver

    65specialconver kennedy-bell MIA

    James,no they did not vary by year.i just hunted these down a few months back after seeing everyone was cutting/splicing thier original harnesses.i understand you gotta do what you gotta do on a car but hacking wires on an original harness is probably the least attractive thing ive noticed on cars at shows...i just hate it,looks like s@*t:shock: nice detailed engine bay,pretty detailed motor,then half a dozen pink/blue crimp connectors with whatever color wire spliced in,wrapped with electrical tape....ughhhh!!!:af:
     
  16. jamyers

    jamyers 2 gallons of fun

    I'm with you, I hate a hacked-up wiring harness (used to work on MG's, for some reason the wiring harness was the first thing people would tear into). Ugh. It's amazing what a couple of dollars of solder, heat-shrink tubine, and a little extra time/effort will do!
     

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