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Battery or Voltage Reg. or ???

Discussion in '40- & 55-Series Tech' started by CardinalFJ60, Aug 13, 2003.

  1. CardinalFJ60

    CardinalFJ60

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    I have an 87 FJ60, 2F, and the Hi-Out SOR alternator (put on last year). The voltmeter has been reading lower than I think it should lately. In the past, it's always read just under the 14v mark and moved a little with blinkers or wipers, no biggie..and if everything was on at a stop light(heater, rear defrost, fog lights, high beams, etc...) it would dip down to just above 12. Never stalling or anything.

    Last night, while driving with just the regular headlights, it read about 12-12.5 and at or just below 12 when stopped at a light...never stalled and idiot light did not come on. Seems low to me.

    How can I tell if it's the battery or the Voltage regulator or something else?

    If it's the battery, what's the feeling on Optima (and what color) vs. the good ol' Interstate Battery?

    Thanks

    Cardinal 87 FJ60
     
  2. CruisinGA

    CruisinGA

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    Its not your battery.
    But on the topic of batterys, I run Optima Yellow Tops. I burned out a Red Top in 6 months because of a faulty charging system. New Alt. brushes and a new volt. reg later I'm golden with my yellow top. 2 yr warranty is good, I had a bad brake light switch and had my brake lights on for 4 hours with car off, still plenty of juice left over to start the car.
    But to diagnose the problem, get a good digital multimeter, and test alternator voltage at idle with no accessories on. Anything less than 13.5 and I would first check all wires and contancts, most importantly the ground on the battery. I had a fried alternator connector as well once. If all the wires check out, replace your voltage reg. (Avail. at Napa). Then come back and give a report.
     
  3. s79bj40

    s79bj40

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    what he said, cept if it was my car i would not discount the battery. If the battery dies, it wont hold a charge and the alternator is constantly at full output just to keep the batt up to spec. So the voltage drops accordingly at idle.

    Its just one of those things thats not an obvious fix without checking everything in the charging system.

    Sam
     
  4. dd113

    dd113

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    Your 60 should have an internal regulator. it can be replaced on its own but I bet it is a PITA. NAPA can test output. I would take it to them first and see.
     
  5. CruisinGA

    CruisinGA

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    When I was having alternator problems, I took it to Napa and it tested fine, 2 weeks later it was completely dead. The brushes were almost gone. Just cause Napa says its good doesn't mean so. But since its new, I doubt the brushes are dying. But yeah go ahead and test it.
     
  6. CardinalFJ60

    CardinalFJ60

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    Had to buy a new multi-meter today - the old one just didn't register right - since I hadn't used it in a long, long time I put in a new battery and tested it on a new 9V battery - the needle pinned!

    I'll give an update tomorrow - thanks for the input!

    Cardinal
     
  7. CardinalFJ60

    CardinalFJ60

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    Hooked up the multi-meter to the battery terminals while not running and then at about 1500 rpms. Not running = 12.6V while running = 14.1v That's with no accessories on....I'll try a "full-load" test tonight.

    It looks like my volt guage doesn't read totally accurately. Not much info here, I know - just an update...

    Cardinal 87 FJ60
     
  8. CruisinGA

    CruisinGA

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    Your battery is either a little drained, or starting to die; it should read ~13 volts fully charged, car not running.
    Test at idle. For a long time my alt. would charge alright at driving RPM's but at idle and lower RPM's I would get barely anything.