Charging problem

Discussion in 'Homesteading Questions' started by pcdreams, Aug 23, 2006.

  1. pcdreams

    pcdreams Well-Known Member

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    got another electrical issue with our 78 chevy pu... I'm guessing maybe its a short in the lighting system. Occasionally the battery will run down and not recharge while driving.. This only happens at night when the lights are on which leads me to believe its not the altenator (that and I had it tested). The other thing thats aggrivating is that it doesn't happen all the time.. only occasionally like maybe once a week.

    My question is how I would check the circuit?
     
  2. End of the Road

    End of the Road Well-Known Member

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    It does sound like the alt. to me. You can go to most any of the auto parts stores (Advance Auto\NAPA\Pep Boys\ ect.) and they can put a meter on your battery and test the battery and the alt. in just a minute. This is a FREE service in hopes that you will buy whatever you need from them. Also make sure the connections to the battery are clean. To do this you have to disconnect them from the battery as it is on the inside of the connections that the most corrision occurs.
     

  3. pcdreams

    pcdreams Well-Known Member

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    guess I should mention Battery and starter was recently replaced (and tested)..cleaned all the connections (starter to alt as well as battery cables) also replaced the worn out plug (starter to alt) as it was giving issues.

    Maybe I'll pull the altenator and have it tested again..
     
  4. Hammer4

    Hammer4 Well-Known Member

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    Check your voltage on the battery with the engine running and the lights ( and blower fan and whatever else electrical on high )...

    Your alternator should have enough charging ability to bring the voltage up to charging levels, 13.5 + volts, maybe a bit more.

    Check the voltage levels with the engine off and everything electrical off and compare.

    If the alternator is charging, the voltage should be higher with the engine running.
     
  5. pcdreams

    pcdreams Well-Known Member

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    turns out it was the altenator.. When I had it checked before it was off the truck.. Found a place willing to load test it on the vehicle and it was only putting out 4 (amps or volts).. OUCH!! It a 63 amp model and she said it should be putting out around 75% of rated amps with a load..

    Well thanks folks. Good as new :)
     
  6. fordy

    fordy Well-Known Member

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    ................I replaced my voltage regulator on my 77f250 , and the new one was defective so none of these electricial components is above being defective . fordy... :)
     
  7. Southernman

    Southernman Well-Known Member

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    Next time you suspect its a alt., start the vehicle then pull the positive cable off the battery (dont let it touch anything) if the vehicle dies, its the alt. if it keeps running its something else.
     
  8. pcdreams

    pcdreams Well-Known Member

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    thats ok on older vehicles (before 81) anything newer and you're apt to blow the brain..
     
  9. idahodave

    idahodave Well-Known Member

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    It's a bad idea to simulate an alternator load dump by pulling the battery cable. If the battery it's connected to is low or has a shorted cell and the alternator is supplying a lot of current, the voltage will soar when the load is removed. I've burned out interior light bulbs doing this.
     
  10. michiganfarmer

    michiganfarmer Max Supporter

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    Exactly! A good battery will have approx 12.4 volts with everythign turned off. Put a cheap multimeter on the battery with the engine running, and the lights on..a good alternator will show a reading at teh battery of at leat 13 volts. You dont need to take the alternator to a shop to test it. You can do it yourself.
     
  11. Southernman

    Southernman Well-Known Member

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    I've used this method for probably 15 years or more and never had a problem with "blowing the brain". Besides, you said it was a '78 Chevy. You don't have to take advice as it is offered, but I have done this many times with no problems.
     
  12. pcdreams

    pcdreams Well-Known Member

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    as have I. I know the risk and take the chance.. Just wanted to let others know as well. No offence intended