Flickering lights

Discussion in 'Diesel Tech' started by Bryant Cottam, Jul 16, 2003.


  1. Bryant Cottam

    Bryant Cottam Farmall Cub

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    First off this forum is more addicting than . . . well . . . something addicting (insert your other addiction). I love all the help offered here.
    Now for the good stuff. When I turn my lights on with my scout at idle they do fine and no problems. However, when I rev up the engine the amp meter guage begins to jump back and forth and simultaneously all the lights begin to go bright and dim in sync with the guge needle. But when I push in the glow plug "trucky" button it stops and they do fine. (yet another use for that astheticaly pleasing "trucky" button) Is this an internal alternator problem or loose belt or what? Any help would be appreciated.

    Thanks.
     
  2. Mike Moore

    Mike Moore Dreams of Cub Cadets

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    Your diesel is possessed by the jealous demon of a gasser!:eek: You need an exorcist, man!

    Seriously, that's odd. This is going to sound generic, but check the ground connections at both ends of the ground cable from the battery to the engine, and also the engine to the frame. It might be grounding back through the glow plug cicuit or sumthi stupid like that. That's odd, though...I'll give you that!:confused:
     
  3. John Donnelly

    John Donnelly Administrator Staff Member Administrator Moderator

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    Clean and adjust your Voltage Regulator as well.

    Mike Moore is correct also.

    The Grounds on Diesel Scouts are worse than the grounds on Gasser Scouts.

    Check the condition of your ground wire from the - terminal on the battery to the connection on the block (should be on one of the motor mount bolts from the mount to the motor itself).

    If the cable isn't attached there, attach it there. If your cable is sketchy, replace it.

    Make sure the ground stud on the body is connected to the Engine flywheel housing as well. This should be a white ten-gage wire that runs from the body to the housing... it is near the starter.

    The voltage regulator needs to have it's contacts cleaned, and the gaps checked and/or adjusted as well.

    Keep on Dieselin',

    John
     
  4. Paul "Misterfixit" Schulz

    Paul "Misterfixit" Schulz Super Mod from Downunder Staff Member Administrator Moderator

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    the brushes in the alternator could also be of concern causing the symptons you describe. :D
     
  5. Baradium

    Baradium Lives in an IH Dealership

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    I vote it being a ground somewhere. Bad grounds can cause some weird stuff.

    So can plugging up a trailer without drying the connector first when it's raining...
     
  6. Bryant Cottam

    Bryant Cottam Farmall Cub

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    Well it's taken a while but I have now grounded everything as much as possible with no nonsense ground wires and the the problem is . . . . worse. Yes, that is right worse. However, now I can say the needle bouncing is more responsive and quick. (that observation did not make me feel better at the time).:mad:
    I am contemplating what to do now. Any suggestions would be appreciated.

    Keep dieseln, even if you are a driving a moving strobe light.:p
     
  7. John Donnelly

    John Donnelly Administrator Staff Member Administrator Moderator

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    You should have a good ground from the engine to the battery.

    You should have a heavy ground strap from the engine to the body.

    THEN....

    Run a ten gage wire from the alternator body "E" (for EARTH) to the (neg) terminal on the Battery.

    This usually cures the pulsing issue.

    Do not confuse the power lug on the back of the alternator with the "E" connection.

    Did you inspect your voltage regulator?

    Keep on Dieselin',

    John
     
  8. drobson

    drobson Farmall Cub

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    I'm with John, check the regulator. These regulators are adjustable, and do have some wear over the years. I had a bad reg in my gas Scout, and it did the same thing you describe. When it would pulse toward "C", the battery was being overcharged, which is bad. Also, clean the connector at the regulator as well. There is also a bullet connector at the starter which is the main feed out of the alternator/ammeter. Check and clean as well. Good luck.
     
  9. Bryant Cottam

    Bryant Cottam Farmall Cub

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    thanks guys I will need to run a 10 guage line off the "E" terminal on the battery. How do you check to see if the regulator is good or not? Thanks for any help.
     
  10. John Donnelly

    John Donnelly Administrator Staff Member Administrator Moderator

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    Bryant,

    Do you have the Diesel Scout engine service manual?

    It is outlined in the electrical section.

    The manual is CTS-2790, and is available from Binder Books, www.binderbooks.com if you don't have it, which you should.

    If you don't, post here, and I will try and get you through it without the manual, but it won't be easy.

    Keep on Dieselin',

    John
     
    Last edited: Sep 17, 2003
  11. Bryant Cottam

    Bryant Cottam Farmall Cub

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    Thanks John, I do have the manual I will look it up tonight.
     
  12. Seanaldo

    Seanaldo Farmall Cub

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    Hello, I realize that this thread is very old but I found out that I have the same problem.. The glow plug button does stop the pulsing but only for as long as I am pressing it. The pulsing is fine at idle but once it is in gear it starts to pulse. The Scout is a 1980 with the SD33T and it was sitting for 8 years before I got it. There was five rats in it and they chewed many wires so I hope that might be my problem. Was there a solution to the problem? Thanks, Sean
     
  13. blue smoke

    blue smoke High Wheeler

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    Did you read and follow the previous posts?
     
  14. Darrel

    Darrel Y-Block King

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    Sean, the OP hasn't been on the forum in years. I would start with the regulator and install a wiring kit. Wires that bad will only give you headaches down the road. The was good discussion on wiring kits a week or so ago.
     
  15. Seanaldo

    Seanaldo Farmall Cub

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    The regulator is brand new.. I have not followed anything yet because the OP didn't say if it fixed it or not. I also don't know a lot about wiring but I do know that the ground wire to the battery is not attached to the block. It is attached to the power steering bracket.. I am not sure where to ground the wire to on the block.
     
  16. Darrel

    Darrel Y-Block King

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    Any bolt hole directly into the block is good. The most important thing is low resistance connections. No paint or corrosion. Make sure you also have a strap between the body and engine.
     
  17. Seanaldo

    Seanaldo Farmall Cub

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    What does the strap have to be made out of? Thank you for responding so quickly! I am afraid of taking out a bolt that shouldn't be removed. I think when this is fixed my parents will be happier about me driving at night!
     
  18. Darrel

    Darrel Y-Block King

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    i didn't realize you were new to all of this. Avoid removing head or intake manifold bolts. Also be careful working around lead acid batteries. Read up on them.

    Grounding straps are usually woven ($5-10 at any auto parts store), but regular battery cables are fine if you happen to have an extra.
     
  19. Seanaldo

    Seanaldo Farmall Cub

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    Yeah sorry I forgot to mention I'm new to cars. It's my first Scout too, so I don't know many tricks yet.. I moved the ground cable to the back of the engine by the firewall. There was a bolt holding a bracket at the back and put the cable there. I do have extra cable so I will probably use that in the meantime until I do get a strap. Thanks, Sean
     
    Last edited: Jul 31, 2014
  20. Scoutoholic91

    Scoutoholic91 Farmall Cub

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    I know this is an older thread but could a ground be why my amp gage pulsates at idol? It’s solid going down the road. I also just installed an electric fuel pump. (By necessity not choice)
     

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