 Different voltmeter readings? |
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| SKL1 |
 Jul 14 2025, 08:44 PM
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Senior Member  Group: Members Posts: 1,717 Joined: 19-February 11 From: north Scottsdale Member No.: 12,732 Region Association: Upper MidWest 
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I've noticed with my '71, which has about 120K miles on it, the voltmeter is pretty much always reading around 11 V regardless of speed or revs.
In my '73, which has about 77K miles on it, it reads 11 or so at start up and for the first couple miles and then goes up to between 12 and 13. I swapped the voltage regulators for the heck of it and it didn't change anything. Is the older alternator from the '71 just worn out?? Not looking forward to changing it with the engine in the car!! |
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| Spoke |
Jul 18 2025, 09:55 AM
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Jerry Group: Members Posts: 7,195 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None
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On my car I measured the battery voltage and recorded the voltage on the center console voltmeter after starting and at higher RPM with headlights off and all exterior marker lights on. The voltage on both did not change with RPM.
The battery was at 13.8V while the voltmeter was 13.0V. I checked the voltmeter before installing a while back and it was within 0.1V from 9V to 16V so the voltmeter is quite accurate. Its placement in the wire harness accounts for the difference in voltage. |
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Posts in this topic
SKL1 Different voltmeter readings? Jul 14 2025, 08:44 PM
Spoke The dash voltmeter on my '71 reads between 12-... Jul 14 2025, 10:46 PM
GregAmy You should check the battery voltage with a DMM.
+... Jul 17 2025, 08:32 AM emerygt350 That dash volt meter is great for reminding you th... Jul 15 2025, 03:49 AM porschetub
That dash volt meter is great for reminding you t... Jul 15 2025, 05:18 PM SKL1 Good to know. Thx guys. Jul 15 2025, 07:25 PM barefoot I substituted the cigar lighter for a USB double p... Jul 16 2025, 02:45 PM 930cabman
I substituted the cigar lighter for a USB double ... Jul 17 2025, 05:53 AM SKL1 My initial entry was a little simplified- I actua... Jul 17 2025, 10:16 AM GregAmy I put the modified engine from my '71 in the 2... Jul 17 2025, 12:32 PM emerygt350 Yes, but you really shouldn't even look at tha... Jul 17 2025, 11:36 AM SKL1 Both engines have their original alternators which... Jul 17 2025, 09:18 PM |
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