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Technical Charging issues on maiden voyage, I am stumped.

Discussion in 'The Hokey Ass Message Board' started by Roothawg, Jun 15, 2014.

  1. Todd M.
    Joined: May 24, 2009
    Posts: 509

    Todd M.
    Member

    I know this is a shot in the dark. Do you have a modern ignition switch? If so check to see if the auxiliary wire is correct.
     
  2. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,573

    Roothawg
    Member

    I don't have a light, so that's why I used a resistor in lieu of.....

    The ignition switch is the original style, but also brand new.

    I have not tried another battery, but shouldn't that only affect the starting and not so much the charging aspect?

    Like I said, the new pigtail is on order. I'll hook up the sensing wire by weeks end. I'll brief everyone after trying that. I only want to do one thing at a time, so I will have a definite answer on what fixed it.
     
  3. I'd also replace that 470 ohm resistor with a 80 ohm/5 watt as per the drawing. The regulator is looking for a specific load through that wire. I know from experience that Ford regulators don't like the wrong value, your GM unit may be the same.
     
  4. skipperman
    Joined: Dec 24, 2002
    Posts: 1,837

    skipperman
    Member

    Just for everyone's library ..... http://madelectrical.com/ ... says it ALL about charging systems and why one wire alts. are BAD !!!

    .... Skip
     
    Ulu likes this.
  5. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,573

    Roothawg
    Member

    I'm not sure where that 470 Ohm 1/2W figure came from. It's what the wiring kit instructions listed.
     
  6. Torana68
    Joined: Jan 28, 2008
    Posts: 1,415

    Torana68
    ALLIANCE MEMBER
    from Australia

    Re
    looked at the first bit if that , they claim they started "the trend" to fit volt gauges instead if amp gauges? As if.....didn't read further
     
  7. Some more things to offer,
    1. Make sure the HEI has a ground strap UNDER the coil. It's the metal strap under the coil, above the cap (sandwiched between the two). It runs to a terminal by the power plug (and you run a wire from it to ground), I've seen coils overheat without it.
    2. I would get a decent amp clamp that has a meter in it, you can use it as a regular meter, check amp loads and check charging amps.
    3. After the sense wire is hooked up, go for a drive with volt meter hooked up, note what the voltage is at when it runs poorly and check the temp of the coil, wires and ign switch.
    [​IMG]
    [​IMG]
     
  8. Just to add, I'm a big fan of warning lights with or without regular gauges. If you want to see them, cole hersee makes nice old looking ones or vintage ones from ebay. If you don't want to see them I've put them on the dash lip facing down and when there's a problem it lights up the floor or your leg, at the very least it will make you look at your gauges. Autometer makes sending units for temp and oil at different settings so you can choose when the lights come on (I use a 15psi oil sending unit, so with a sbc, 20/50 oil 1 qt low the light comes on).
     
    jbrittonjr likes this.
  9. BobMcD
    Joined: Jan 25, 2013
    Posts: 322

    BobMcD
    Member

    The first thing to make sure is that you have a good battery. Have it tested to verify it's good. As some of the others have said, don't disconnect the battery when the engines running as you can damage the alternator. A fully charged lead acid battery should have between 12.6 and 12.7 volts with the key off. If you measure higher than that, it means one of two things. The battery could have surface charge or your meter is off. Turn the loads on for 30 seconds with the key off to remove the surface charge. Turn the loads off and check the battery voltage again. If you have more than 12.7, your meter is probably off.
    With the engine running you should be reading around 13.6 to 14.7 volts. The newer alternators will run higher into the 15-16 volt range. As loads are turned on the voltage goes down and the amperage goes up when the engine is running. . Ideally the voltage at the alternator should be the same at the battery, with the engine running and the loads turned on. If it's not, you have a voltage drop on either the postive or the negative side. You can take your meter and measure the drop by putting one lead on the postitive post of the battery. The other lead goes to the battery terminal on the alternator. You should read less than 1/2 volt. If it's higher you have too much resistance of the positive side. Now do the same thing on the negative side. One lead on the negative post and one lead on the alternator case. With the engine running and loads on you should have less that 1/2 volt. If it's higher you have a poor ground. You can also check for a key off drain by removing the negative battery cable and measure voltage between the negative terminal on the battery and the battery cable. Check the battery and verify your meter. Run the tests and let us know what you come up with.
     
  10. Good stuff there!
    Solid troubleshooting and done in less than a min giving you a clear and decisive direction to head in towards chasing the problem down.
     
  11. gimpyshotrods
    Joined: May 20, 2009
    Posts: 23,315

    gimpyshotrods
    ALLIANCE MEMBER

    For warning lights, I like jewled glass pilot lamps from Fender guitar/bass amps. They are a good size, come in several colors, and look old-fashioned. There are both 6v and 12v bulbs that fit them, depending on how you roll.
     
  12. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,573

    Roothawg
    Member

    Thanks Bob. As stated earlier, good solid advice.
     
  13. Ulu
    Joined: Feb 26, 2014
    Posts: 1,775

    Ulu
    Member
    from CenCal



    I was going to suggest this as well. Typically, on a car with a "key off" drain I'll wire a tail light bulb between the negative post and terminal. If it glows there's a substantial drain. If it doesn't glow I'll start wiggling all the wires until it does glow, indicating where the short circuit is.

    This works well for tracking down shorts in most cars.
     
  14. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,573

    Roothawg
    Member

    There's no drain. It can sit for weeks and still bust right off. It's only when it's running.
     
  15. Ulu
    Joined: Feb 26, 2014
    Posts: 1,775

    Ulu
    Member
    from CenCal

    That's good news.

    I heard many good things about the Optima battery. I'm surprised yours failed. I was planning to buy one for my truck, but recently they disappeared from the shelves at Costco. Maybe they've had some quality control issues of late?
     
  16. A voltage draw won't tell you much, if your going to do a parasitic draw test you need to check out the amps (or milliamps).

    I have to look at those, I've just been buying the old Dialco ones.
     
  17. Ulu
    Joined: Feb 26, 2014
    Posts: 1,775

    Ulu
    Member
    from CenCal



    It'll tell you that your battery is gonna be dead soon. ;)
     
  18. skipperman
    Joined: Dec 24, 2002
    Posts: 1,837

    skipperman
    Member

    Try reading it in it's ENTIRETY ...... ya might LEARN something .... ;)
     
  19. What's the scoop here ?
     
  20. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,573

    Roothawg
    Member

    Sorry guys, we are prepping my vintage travel trailer for a 2 week journey. I haven't messed with it lately. I will keep you posted.
     

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