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By PF Arcand - 12 Years Ago
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Currently have an Amp guage in my 57s stock generator electrical system. It has been suggested by some that a Volt meter is a better choice, requiring less heavy wiring etc.. Currently it has 10 G wiring from the solenoid, then along the cross member & on thru to the under dash guage & then back to the regulator. Roughly 18' or more of wire. As wired it does not show a minus draw either. So, is a Volt meter the better way to go? And what is the best way to wire in a volt meter? Thanks
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By Hollow Head - 12 Years Ago
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http://www.autometer.com/tech_faq_answer.aspx?sid=1&qid=5 From battery + via 5A fuse to meter and from there to ground somewhere.
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By NoShortcuts - 12 Years Ago
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PF Arcand (5/7/2012)
Currently have an Amp gauge in my 57s stock generator electrical system. It has been suggested by some that a Volt meter is a better choice, requiring less heavy wiring etc. Is a volt meter the better way to go? Thanks
It is possible for the charging system to be putting out the correct voltage (pressure) reading, but not be producing the appropriate amount of electrical current (electron flow). 
I would recommend using the amp meter rather than the volt meter. IMO it will give you the better measure of what is most apt to be a problem in monitoring keeping the battery properly charged and electrical system properly functioning.
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By The Master Cylinder - 12 Years Ago
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My personal safety of running a voltmeter over an ampmeter out weighs anything that can be said about using a ampmeter. I just don't like the thought of 75-100 amps (your alternator output) running through my dash inches above my legs. 
But that's just me.
There are other reasons to run a voltmeter over a ampmeter. For your reading pleasure... http://www.egauges.com/ATM_Tips.asp?TipPage=voltmeterammeter.htm
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By The Master Cylinder - 12 Years Ago
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Oh, back to the question. I ran a wire from the Acc post on my ignition switch to the + side of the voltmeter, then ran a wire from the - side to ground. needs to be a switched 12v so there is no drain on battery when car in not running.
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By Hollow Head - 12 Years Ago
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The Master Cylinder (5/8/2012)
Oh, back to the question. I ran a wire from the Acc post on my ignition switch to the + side of the voltmeter, then ran a wire from the - side to ground. needs to be a switched 12v so there is no drain on battery when car in not running.Yes, from the switched 12 volt! It's been so long since working with street cars so I forgot that discharging effect. Dealing with dragster and battery kill switch does that  .
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By NoShortcuts - 12 Years Ago
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The Master Cylinder (5/8/2012)
My personal safety of running a voltmeter over an ampmeter out weighs anything that can be said about using a ampmeter. I just don't like the thought of 75-100 amps (your alternator output) running through my dash inches above my legs.
GOOD POINT! ...and as Paul indicated, we're talking about perhaps 18 feet of a heavy gauge wire because of the amps being carried.
Remembering that under the right circumstances less than a half an amp of current can kill you, I retract my previous recommendation of using an ammeter. THANKS for the article Master Cylinder! 
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By Doug T - 12 Years Ago
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I don't know about everybody else but I can not feel 12 volts DC and it is highly unlikely that a person could be killed by that low voltage. You can not have high enough current to do yourself any damage with 12V, your resistance is too high. The concern about heavy gauge amp meter wiring is relevent if the insulation is bad and the bare wire grounds. Then the battery is shorted out and the high resulting current could heat the wire and insulation enough to start a fire. But remember that the ignition switch also is wired driectly to the battery so the same concern about insulation obtains.
That said I go with a volt meter also. I do think it tells you more especially if the battery is going bad. Then you can see the voltage drop off as the starter trys to kick in. I wonder why amp meters were so popular in the '50's and '60s when the little two gauge panels of oil press and amp meter were sold and installed to replace idiot lights.
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By YellowWing - 12 Years Ago
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Something nobody has mentioned yet. With the voltmeter installed you can shorten or install new wiring between the alternator/generator and the battery or battery lug on the starter solenoid. The shorter run will give you less voltage loss on the charging circuit. Use a fuse or circuit breaker on this wire, could save you a lot of trouble in the future. Mike
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By bergmanj - 12 Years Ago
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Folks, Can anyone here tell me what guage wire the heavy one is between the generator and regulator? I have extensive experience in electronics, and have another idea to present here regarding using a "shunt" ammeter with "light-guage" remote sensing; and, I need to know that wire size to do a little figuring before I present the thought. Regards, JLB
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By The Master Cylinder - 12 Years Ago
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Doug T (5/9/2012)
I don't know about everybody else but I can not feel 12 volts DC and it is highly unlikely that a person could be killed by that low voltage.
I wasn't referring to the voltage, it's the AMPs that do the damage.
Which brings up a BAD thing that happened to a friend... while working around a battery this friend was wearing a Gold wristwatch. Gold is an excellent conductor. I'll let you imagine the results when is his watch ground the positive battery pole. Please be careful folks.
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By bergmanj - 12 Years Ago
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Master, Lest there be some misunderstanding here regarding various metals and their electrical conductivity: Of the common metal conductors at room temperature, silver is best , next is copper, and gold is further on down the charts; gold is typically used on connector contacts for it's resistance to corrosion, rather than its conductivity. Regards, JLB
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By rick55 - 12 Years Ago
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Master cylinder, wrist watches are dangerous around batteries as you can get a nasty burn, but by far the worst thing around a battery, especially one that has recently been charged, is a cigarette or naked flames. A friend of my son learnt this the hard way. He lost the sight in one eye when a battery he was charging exploded. He was smoking and leant over the battery to see if the cells were bubbling. Something he had done a hundred times before.
A battery gives off hydrogen gas when it is charging and if you want to see explosive, this is by far the worst. Care should be taken when connecting jumper leads for just this reason.
Regards
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By The Master Cylinder - 12 Years Ago
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bergmanj (5/11/2012)
Master,
Of the common metal conductors at room temperature, silver is best , next is copper, and gold is further on down the charts;
Regards, JLB
Thanks for the lesson JLB. Haha, Knowing him it would have been a Gold plated silver watch anyway. My point was gold or any metal when grounding a car battery gets hot quick and when it is around your wrist thing get real BAD fast.
Rick, good point and another reason not to smoke (unless it's your tires).
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By DryLakesRacer - 12 Years Ago
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Bergmanj. The wire is normally an AWG 10. Which is good for 30 amps continously and up to 40 without damage. When a higher amp generator/alternator is used a larger wire to the regulator or battery should be used. On my race car I use a single wire 60 amp alternator and a #6 wire which goes directly to the starter soleniod post. All are correct about amperage killing but it take the pressure of higher voltage than 12 VDC. I have worked with 135 VDC and up to 3 phase 500,000 VAC for 45 years and have respect for all of it. Just remember DC will never let go amd single phase AC will let you go 60 times a second if you are fast enough PS: I personally like a voltmeter in my cars. Only my 56 Vic does not have one
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By pegleg - 12 Years Ago
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Just remember DC will never let go amd single phase AC will let you go 60 times a second if you are fast enough I usually let go when I fall over!
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By bergmanj - 12 Years Ago
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And a wedding ring (or other metallic jewelry) in combination with a "hot" cigar lighter under the dash can cause "issues" for the bearer too! My personal rules for working around any kind of electricity for well over 45 years have always been one-hand-in-back-pocket; and, no metallic jewelry of any kind. "Lose respect, and lose your life!" By the way, 60 Hz current "lets-go" 120 times per second on each of its "zero-crossings", not 60. Regards, JLB
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By DryLakesRacer - 12 Years Ago
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Bergman to you I salute your respect of electricity. I too in my 45 years in power supply station do not wear any jewelry and with that said am still married to my bride since 1966. I will say that I have given a little back with the highest voltage being 480 that bit me a few times. I however had to give 2 hands to the company; I just needed to make sure I knew where I was putting them. All in all I am currently glad cars of today do not have amp meters in the dash because of the electrical loads we DO have today. It's not unheard of to have 140 amp alternators. Look at these guys with the killer stereos most need 2 alternators to keep up. A few of my 50's cars burned up the wiring with grounds and hi current and all of them came up under the dash...JD
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By bergmanj - 12 Years Ago
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DryLakes, Seems that you and I have had similar backgrounds! I've also worked at a Utility generating station of about 1,200 MW size (4 units - 2x60MW, 1x350MW, & 1X650MW), coal-fired; was an I & C worker for them. Have also worked jobs as TV Broadcast Transmitter Engineer, genuine electronics manufacturing and test engineer (gov't & military equipment manufacturing - also sub'd for the likes of McDonald Douglas on the test flight recorders for their qualification tests of the FA-18 some 20+ years ago; China Lake Naval Weapons Center - QF4N FSAT on-board flight control box; Brunswick Aerospace on the 1st gen of cruise missle flight computers [have an old one in my office as we speak]). Spouse and I also been hitched for 45+ years, too! Interesting! As for the metering: I was heading toward using a short section of the 10GA wire as a shunt for a dash shunt-meter for also indicating charge/discharge; this would have fused small-guage sensing wires from the shunt (under the hood) to the millivoltmeter (calibrated as an ammeter), and be much more relatively "safe" for under-dash use. I still like Ammeters in addition to the dash voltmeters: Give a "complete" picture of the charging system. 10GA wire gives 0.25V across 11.78" of wire for 25 Amps according to the copper wire-guage charts for resistance. I know that this isn't "precise"; but, I've yet to see any "precise" dash guage in any ordinary vehicle anyway; so, it would be "good enough" for mos all of us to "guage" the system in operation. Regards, JLB
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By DryLakesRacer - 12 Years Ago
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Bergman..I worked for the Southern Calif Edison for 28 years before they retired me out at 52 in 1996. A good package so I took it. I went through their Electrical Apprentice program and spent 13 years as an electrician and 15 as a foreman. I worked on 90 Megawatt peaking units all the way to starting both San Onofre Nuclear 1000 Meg units. I worked on coal, oil, natural gas and jet fuel units. Most of my time was with oil and gas working in a traveling overhaul crew. After retirement in '96 I freelance/contracted for a few years and then went back in 2003 to the Huntington Beach Generating Station which was bought by AES LLC in 2000. I am currently an electrical tech. (no more supervising for me). Nothing like working in Surf City USA right on the beach. We currently running 4 units with a total of 900 megs. The oldest is 1958 and the newest 1960 so I am right at home since I love the old stuff. Running a GMC 6 powered LSR roadster, have my dads 1939 Indian which I restored in 2000, (He bought it in 1943) and just recently purchasing a restored 1956 Victoria (Mom had a new one in 1956-61) I am about ready to drive/ride into retirement again at 68. This forum is great and I read everything and share stuff I know....................JD
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