Wiring a voltmeter

Started by Topsterguy, July 06, 2016, 09:59:18 PM

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Topsterguy

What's the best way to wire a voltmeter to get a true reading?  My Autometer voltmeter seems to  be reading high ( 16 V) when the reading at the battery is actually about 13.8 -13. Right now I'm taking the power to it off the ignition switch.  Thanks!
"If a man is alone in the forest and speaks, and there\'s no woman around, is he still wrong?"

58 Yeoman

Are you sure the gauge is accurate?
I survived the Hyfrecator 2000.

"Life is what happens when you're making other plans."
1967 Corvair 500 2dr Hardtop
1967 Corvair 500 4dr Hardtop
Phil

Topsterguy

Quote from: "58 Yeoman"Are you sure the gauge is accurate?
I checked the voltage across the battery and it was about 13.8-14 and the gauge in the car read about 14-16 as close as I could see, but the stock ammeter is still hooked up ( it's a 69 Dart ) and it bounces around a lot. I've never had problems with Autometer gauges before but I guess it's possible. Does the regulator regulate the voltage before or after the battery? Wondering if the voltage is varying at the votmeter before the regulator then lowered at the battery ???
"If a man is alone in the forest and speaks, and there\'s no woman around, is he still wrong?"

enjenjo

The gauge is wrong. If it's 13.8 at the battery, it will be that or slightly less at the ignition switch.
Welcome to hell. Here's your accordion.

Topsterguy

Thanks guys !       I talked to a buddy today with the same car and he had the identical problem ( volt gauge reading high and went higher with increased revs) , took it to an electrical shop, and they said it was due to the regulator needing a relay in line with one of the wires going to it, so they installed it and it was fine after that!!??  Waddythink ????
"If a man is alone in the forest and speaks, and there\'s no woman around, is he still wrong?"

enjenjo

Quote from: "Topsterguy"Thanks guys !       I talked to a buddy today with the same car and he had the identical problem ( volt gauge reading high and went higher with increased revs) , took it to an electrical shop, and they said it was due to the regulator needing a relay in line with one of the wires going to it, so they installed it and it was fine after that!!??  Waddythink ????

I guess if that did it, it's great.
Welcome to hell. Here's your accordion.

Topsterguy

Quote from: "enjenjo"
Quote from: "Topsterguy"Thanks guys !       I talked to a buddy today with the same car and he had the identical problem ( volt gauge reading high and went higher with increased revs) , took it to an electrical shop, and they said it was due to the regulator needing a relay in line with one of the wires going to it, so they installed it and it was fine after that!!??  Waddythink ????

I guess if that did it, it's great.

:)  I guess I'll find out tomorrow, eh !  Thanks again!
"If a man is alone in the forest and speaks, and there\'s no woman around, is he still wrong?"

Crosley.In.AZ

should be interesting.  Never heard of a relay needed for a voltage gauge install.

Will interested in the progress & out come of it
Tony

 Plutophobia (Fear of money)

Topsterguy

I'm guessing the whole problem is the fact that the stock ammeter is still hooked up causing a drop in voltage across it  which would affect the regulator and the volt meter....right ???
"If a man is alone in the forest and speaks, and there\'s no woman around, is he still wrong?"

wayne petty

please print and perform this complete test to verify you don't have other electrical issues causing the 16 volt reading..

http://i.imgur.com/WMDprhm.jpg

you would not believe how many cars with electrical system issues i have found the problem and made the car work better.. it only takes about 5 minutes to perform on most cars..

test 5 is important.. but hard to perform on cars prior to 1995..  but almost all cars and trucks have power distribution studs under the hood..

some 60s GMs use the 2 big screws on the horn relays..  

if you have to extend the test.  use a single jumper cable. from the battery to extend the reach of your meter..

i would want to add an additional test... from the positive battery post to the positive connection on the volt meter..

i would also do that from the alternator output to the volt meter  positive..

less is better.. if you have questions.. post results by number.  and or where you tested from

there have been major issues where the only negative cable connects to the engine block...  all cars and trucks need at least 3 ground connections..

Negative battery cable to the block..
Negative battery to the body.
Engine to the firewall.

those are tests 2, 3 and 4..  those take less than a minute but must be performed with the alternator charging and the headlights on..