Analog Voltmeter Gauge Readings

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Oct 31, 2011 | 01:50 PM

briankeery

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From: Midland Ontario

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Analog Voltmeter Gauge Readings

Greetings,

OK probably not a big deal but putting my mind at ease will definitely help me out today. I have a '79 L-48, auto, no air. The voltmeter gauge shows the needle just sitting on the edge of the "redline" area (I'll assume 15.5 VDC) almost all the time(99% - sometimes in the red - but never pegged), which has led me to think I've got a regulator that's giving up the ghost! Alternator output voltage at idle = 14.33 VDC, Battery voltage at idle = 14.13 VDC, Battery voltage parked = 12.6 VDC.

Car starts every time, did have a drain issue earlier this summer when I first purchased, but that was determined to be a faulty delay board for the interior lights - once bypassed I've had no further issues.

I assume my voltmeter should show my battery reading of approx 14VDC......so my question is : Is this just a gauge that's developed some personality, since these multimeter readings seem reasonable to me. Is it worth swapping it out for a new one for $75 to see if I can drop a needle 1-1.5 VDC?

Thanks

Brian

Oct 31, 2011 | 02:05 PM

Ganey

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From: CORVETTE 77 385 C.I. TEXAS

My 77 voltage has always read slightly high. You could reposition the needle.

Oct 31, 2011 | 02:05 PM

jnb5101

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From: charlotte north carolina

it's halloween! your car's meter is possessed! tomorrow it will be ok. spend the $75 on candy!

Oct 31, 2011 | 02:14 PM

Jud Chapin

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From: Wellington, FL

St. Jude Donor '11 thru '25

If all is working well, I wouldn't touch it.

Oct 31, 2011 | 05:11 PM

7T1vette

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From: Crossville TN

Just use a cheap voltmeter to measure battery voltage while reading the car's gauge. If they agree, then there is a problem with your alternator (regulator is defective) or the 'sensing wire' is broken or not wired properly to the alternator. A running vehicle with a fully charged battery will show about 13 volts going to the battery. If you are constantly sending 15 volts to the battery, it will wear out quickly.

Oct 31, 2011 | 06:04 PM

briankeery

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From: Midland Ontario

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Charlie, as stated in my original post, I did use a multimeter to verify output voltage at alternator and input voltage to the battery.....these readings are on line with spec readings. My question has to do with the fact my gauge is out 1-1.5 VDC.

Thanks

Brian

Oct 31, 2011 | 11:25 PM

7T1vette

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From: Crossville TN

Reading never was my 'strong suit'. But, the charging voltage is still higher than I would have expected for a fully charged battery. What does the meter read when the ignition is in the "ON" position with the engine not running? Does the gauge in the car still check 1.5 volts higher than the multimeter check on the battery?

Nov 1, 2011 | 05:26 PM

briankeery

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From: Midland Ontario

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Right at attention at 12 VDC.......multimeter as stated before shows 12.6VDC, so that's why I'm thinking this gauge is out of calibration.....now considering it's 32 years old and working at all, I guess I shouldn't be too pissed off.......but I basically just wondered if other people had experienced the same thing as their vehicles have aged.