 Voltage discrepancy, WTF? |
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| saigon71 |
 Dec 11 2018, 06:17 PM
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#1
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Senior Member  Group: Members Posts: 1,998 Joined: 1-June 09 From: Dillsburg, PA Member No.: 10,428 Region Association: MidAtlantic Region 
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As long as I can remember, when driving at night in the 914, my center console voltmeter hovers right around 12V when cruising with the lights on. When I hit the brakes, it drops well below 12V...anything else drops it even lower.
I'm running an Optima Red Top near the end of it's service life and want to make sure my charging system is healthy before popping on a new AGM battery. I had been considering switching to LED headlights and brake lights to lower the current draw. I hooked up the VOM at the battery and did a load test with the car running, adding an accessory at a time. With headlights, brake lights and aux fan on the voltmeter in the center console read just over as 10 volts, while the VOM hooked to the battery showed 12.58V. Is this discrepancy normal?   |
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| North Coast Jim |
Dec 11 2018, 07:21 PM
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#2
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Member Group: Members Posts: 323 Joined: 11-December 15 From: Northern Ohio Member No.: 19,450 Region Association: MidAtlantic Region
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You also could have lost the ground connection within the appearance group wiring. Had the same problem. All is well after I reconnected the ground wire
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| dr914@autoatlanta.com |
Dec 12 2018, 09:09 AM
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#3
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914 Guru Group: Members Posts: 7,850 Joined: 3-January 07 From: atlanta georgia Member No.: 7,418 Region Association: None |
QUOTE(North Coast Jim @ Dec 11 2018, 06:21 PM)  You also could have lost the ground connection within the appearance group wiring. Had the same problem. All is well after I reconnected the ground wire I agree check the aux instrument wiring harness ground connection under the console shift base plate, remove clean and plug back in. Volt meter should read 13.6 at idle with no load |
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Posts in this topic
saigon71 Voltage discrepancy Dec 11 2018, 06:17 PM
toolguy perfectly normal and as expected. . old wire with... Dec 11 2018, 06:23 PM TheCabinetmaker Nothing to do with old wires! They worked like... Dec 11 2018, 06:56 PM adolimpio Ohm's law. Voltage drops as current passes thr... Dec 11 2018, 07:09 PM
PanelBilly I added a new ground wire to mine and that fixed i... Dec 11 2018, 08:08 PM GregAmy Is this discrepancy normal?
Yes. This is why I de... Dec 11 2018, 08:21 PM campbellcj I'm fighting the same issue now too, and it wa... Dec 12 2018, 08:56 AM ClayPerrine The volt meter in the center console is nowhere ne... Dec 12 2018, 09:00 AM Spoke
With headlights, brake lights and aux fan on the ... Dec 12 2018, 08:49 PM
Dave_Darling I like to say that the voltmeter is there "fo... Dec 12 2018, 10:48 PM |
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