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High Voltage at the Battery.. or.. new real time volt monitor.. :)-

Discussion in 'Subaru Sambar' started by J Dexter, Apr 30, 2017.

  1. J Dexter

    J Dexter New Member

    I'm not sure about a reading I'm getting at the battery on a 92 Sambar truck and wonder if anyone else is seeing the same thing - or - has a positive terminal long term shorting to frame burnt something important upstream?

    Basically - started up the truck on a charged battery and fresh ground cable, had been having some weird electrical problems. While I was in there noticed the positive lug on the battery was pretty much in contact with the battery box (metal) most of the time. No sparks or anything, but.

    So, flipped the lug and put a shim under the backside of the battery (honda type 511 battery) to lift/lean it clear of the back of the battery box. Truck fired right up, volt meter on the terminal showed 14 or so volts. Perfect.

    Then, decided to check the draw in case the short had killed the alternator - so fired up the blower and checked.. showing 16 volts battery terminal.. then, the wipers and lights - almost 19 volts.

    Took it out this evening - no change in headlight brightness could actually see the dash lights and it was firing evenly again.

    Please excuse if this is correct, hadn't checked voltage at the battery itself yet - but having expected a steadish 14v constant - thought best to ask here.

    Thanks in advance - J Dexter
    The Stormy North Atlantic
     
  2. fmartin_gila

    fmartin_gila Well-Known Member

    An Alternator during charging the battery right after starting should only put out 14.3/14.5 Volts and your system voltage should be in that area or slightly less depending on resistance & load. Are you sure the meter you are using is accurate. Electrical items will not last very long running that high voltage and the battery should be very warm or hot to the touch, should also smell somewhat bad due to the sulphuric acid boiling.

    Fred
     
  3. J Dexter

    J Dexter New Member

    Thx for reply Fred. Nothing seemed hot, so ran it over to Halifax AutoSports and Martin's Fluke reads 14.4 steady on warm up no matter what I turn on. So, perhaps I do have a new voltage monitor where once I had cheap multimeter..

    I'll check it again using mine to make sure it wasn't a one off or an operator error - because oddly - real time voltage draw information would be weirdly helpful over the next month.

    J Dexter
    The Stormy North Atlantic
     
  4. fmartin_gila

    fmartin_gila Well-Known Member

    14.4 Volts sounds good and with the varying load indicates that the Voltage Regulator is functioning properly. Would seem to me that your original reading of 19 Volts was erroneous. If the battery was jumping around and intermittantly shorting the Pos terminal to ground, it would cause some weird things to happen. Seems as if you have caught it in time before it caused you some major problem.

    Fred
     
  5. J Dexter

    J Dexter New Member

    Entirely possible Fred, it's a very old inexpensive Princess Auto multi-meter and it's seen some rough service. What was curious was with the positive terminal cleared and the ground repaired it was correctly reporting the total additional draw from the lights, blower and wipers as they were turned on and off or run together when the engine was warmed up.

    On your reply, before I took it over to the shop, I gave it a good high rev run around town to see if the battery heated up and to clear as much soot out of the engine as possible given I expected it has been grounding out and misfiring for a couple of months (many more). Battery wasn't warm and it finally was making full revs easily - again, no change in headlights or blower speed as the the revs went up or down.

    I think I'll try to find a little analogue volt meter to fit in one of the dash cutouts just in case the regular has been damaged to the point were it -sometimes- free flows. Y'know.. in case its that very worst kind of electrical problem/curse.. :)-

    Question - anyone know where I can find/if I can put on a 60 or 80 amp alternator with an internal regulator (I believe stock runs 40 amps - don't know if the regulator is internal).

    J Dexter
    The Stormy North Atlantic
     

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