Go Back   The Ford Barn > General Discussion > Late V8 (1954+)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 11-27-2020, 09:21 PM   #1
ahshoe
Senior Member
 
Join Date: May 2010
Location: Eastern Iowa
Posts: 311
Default Voltmeter wiring

Lost my direction from my guage trio wiring.Question how is a aftermarket voltmeter guage to a car with a generator?
ahshoe is offline   Reply With Quote
Old 11-27-2020, 09:50 PM   #2
dmsfrr
Senior Member
 
dmsfrr's Avatar
 
Join Date: Aug 2012
Location: Abq, NM
Posts: 2,654
Default Re: Voltmeter wiring

Does the voltmeter have two terminals, not connected to the housing that holds the gauges or anything else?
If so...
and the vehicle is Negative ground, the Battery / Plus terminal of the voltmeter would connect to the Accessory terminal of the Ignition switch, and the Negative voltmeter terminal to a good Ground.

If the vehicle is Positive ground, the Negative terminal of the voltmeter would connect to the Accessory terminal of the Ignition switch, and the Plus terminal of the voltmeter connects to a good Ground.

.

Last edited by dmsfrr; 11-27-2020 at 10:11 PM.
dmsfrr is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 11-28-2020, 07:11 PM   #3
Daves55Sedan
BANNED
 
Join Date: May 2010
Location: Granite City, Illinois
Posts: 2,229
Default Re: Voltmeter wiring

If you want the voltmeter inside the car (under the dashboard or somethin like that), I would trace down the big wire that connects from the starter solenoid and goes to the dashboard. Find out if it goes to a "Batt" terminal on the headlight switch first or goes to "Batt" terminal on ignition switch. Whichever one that wire land upon, double-lug that terminal for the power lead on your volt-meter, that way you will read actual full amount of battery voltage available at the battery.
The other lead off the voltmeter should be connected at a ground lug that is directly or indirectly connected to the battery or car frame. Make sure car battery has good clean ground connection to firewall and car frame.
If installing volt-meter under the hood, you can connect the voltmeter power lead to the first terminal the battery power cable lands on (likely the starter solenoid). May need to use a large ring-tongue terminal on your volt-meter power lead to connect to starter solenoid. Then run the ground wire down and connect to same lug on the engine or car frame that the battery ground is jumpered to. Mount volt-meter on isolated standoff bracket (insulated from metal fender apron or firewall).
Daves55Sedan is offline   Reply With Quote
Old 11-28-2020, 09:36 PM   #4
paul2748
Senior Member
 
paul2748's Avatar
 
Join Date: May 2010
Location: Midland Park, NJ
Posts: 2,902
Default Re: Voltmeter wiring

You can connect a voltmeter to any electrical source. The accessory terminal of the starter switch is a good source. I would recommend a 12 gauge wire, but a 14 will do just as well. The gauge has to be grounded. I grounded mine to the dash.


I have put voltmeters in three cars that originally didn't have them, and that is how I did it.. Absolutely no problems


Assuming a 12 volt system - a 6 volt system may be different.


It isn't like installing a amp meter.
__________________
48 Ford Conv
56 Tbird
54 Ford Victoria
paul2748 is offline   Reply With Quote
Old 11-28-2020, 10:03 PM   #5
miker98038
Senior Member
 
miker98038's Avatar
 
Join Date: Mar 2013
Location: Kent, WA. Tucson, AZ
Posts: 873
Default Re: Voltmeter wiring

6 or 12 volt, I like the voltmeter on the run or accessory position on the key. That way its not a continuous draw, even if not much. Either way, if it's not on a fused wire, fuse the hot side as close as possible to the connection.

Checking the voltage at the battery and comparing it to other places is a good idea on old wiring. If you've got 6.6 or 13.7 volts (or whatever) running at the battery and much less than that at the ignition there's another connection that needs to be cleaned up.

All the 50's cars I've worked on had wiring where the insulation was starting to crack and fail, and many connections that were marginal. Look close when you're hooking it up.
miker98038 is offline   Reply With Quote
Old 11-28-2020, 10:59 PM   #6
dmsfrr
Senior Member
 
dmsfrr's Avatar
 
Join Date: Aug 2012
Location: Abq, NM
Posts: 2,654
Default Re: Voltmeter wiring

Sponsored Links (Register now to hide all advertisements)
Quote:
Originally Posted by ahshoe View Post
Lost my direction from my guage trio wiring. ...
Quote:
Originally Posted by Daves55Sedan View Post
If you want the voltmeter inside the car (under the dashboard or somethin like that), I would trace down the big wire that connects from the starter solenoid and goes to the dashboard. Find out if it goes to a "Batt" terminal on the headlight switch first or goes to "Batt" terminal on ignition switch. Whichever one that wire land upon, double-lug that terminal for the power lead on your volt-meter, that way you will read actual full amount of battery voltage available at the battery.. . .
Quote:
Originally Posted by miker98038 View Post
6 or 12 volt, I like the voltmeter on the run or accessory position on the key. That way its not a continuous draw, even if not much. Either way, if it's not on a fused wire, fuse the hot side as close as possible to the connection. ...
Yes, a fuse in the power wire to the voltmeter is highly recommended, and if the power wire for the meter is connected to one of the large "battery" wires, yes the meter will always be on, draining the battery when the car is parked.
dmsfrr is offline   Reply With Quote
Old 11-28-2020, 11:51 PM   #7
ahshoe
Senior Member
 
Join Date: May 2010
Location: Eastern Iowa
Posts: 311
Default Re: Voltmeter wiring

Is the ACC. terminal hot all the time or only when the key is in the ON position?
ahshoe is offline   Reply With Quote
Old 11-29-2020, 12:07 AM   #8
dmsfrr
Senior Member
 
dmsfrr's Avatar
 
Join Date: Aug 2012
Location: Abq, NM
Posts: 2,654
Default Re: Voltmeter wiring

Only when the key is in either the On or the Accessory position. (unless the switch is faulty)

.

Last edited by dmsfrr; 11-29-2020 at 12:14 AM.
dmsfrr is offline   Reply With Quote
Old 11-29-2020, 10:00 AM   #9
ahshoe
Senior Member
 
Join Date: May 2010
Location: Eastern Iowa
Posts: 311
Default Re: Voltmeter wiring

Can anybody tell me which color wire is the ACC. wire on the back of a 1961 Galaxie ignition switch? I have a molded rubber grommet of sort covering all the ignition switch terminals. There is threaded stud coming out the back that does not have any wires on it. Is this an ACC terminal or do I have to splice into another colored wire. If so what color wire? Also what size inline fuse should I use when tapping into this for my Voltmeter? Thanks so far for all the info.
ahshoe is offline   Reply With Quote
Old 11-29-2020, 10:10 AM   #10
5851a
Senior Member
 
Join Date: Oct 2014
Location: NE Iowa
Posts: 897
Default Re: Voltmeter wiring

Yes I believe it is, as acc were added they would be added to the stud. Check with test lamp.
5851a is online now   Reply With Quote
Old 11-29-2020, 10:57 AM   #11
dmsfrr
Senior Member
 
dmsfrr's Avatar
 
Join Date: Aug 2012
Location: Abq, NM
Posts: 2,654
Default Re: Voltmeter wiring

Here's a link to a collection of '57 to '65 Ford wiring diagrams.
http://www.oldcarmanualproject.com/t.../fordindex.htm

'61 Fairlane & Galaxie...
http://www.oldcarmanualproject.com/t...re5765-206.jpg

In the diagram, the Acc wires coming from the ignition switch are Black w/ a Green stripe.
dmsfrr is offline   Reply With Quote
Old 11-29-2020, 01:35 PM   #12
ahshoe
Senior Member
 
Join Date: May 2010
Location: Eastern Iowa
Posts: 311
Default Re: Voltmeter wiring

Any idea on the fuse size on that hot + ,Voltmeter wire?
ahshoe is offline   Reply With Quote
Old 11-29-2020, 04:43 PM   #13
dmsfrr
Senior Member
 
dmsfrr's Avatar
 
Join Date: Aug 2012
Location: Abq, NM
Posts: 2,654
Default Re: Voltmeter wiring

Quote:
Originally Posted by ahshoe View Post
Any idea on the fuse size on that hot + ,Voltmeter wire?
Are there any panel lights on that three instrument cluster? Maybe on their own circuit?

The only load on that fuse will be the meter itself, so a really small fuse will do. 1/2 amp may be overkill?
dmsfrr is offline   Reply With Quote
Old 11-29-2020, 05:10 PM   #14
Daves55Sedan
BANNED
 
Join Date: May 2010
Location: Granite City, Illinois
Posts: 2,229
Default Re: Voltmeter wiring

Quote:
Originally Posted by paul2748 View Post
You can connect a voltmeter to any electrical source.
True, but if you connect the voltmeter at a terminal downstream of circuits feeding loads, the voltmeter will not measure the volt-loss of the sum total of those circuits.
That's why I tried to describe connecting the voltmeter power lead to the first electrically continuous power wire from the battery ahead of circuit taps feeding loads.
Daves55Sedan is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 05:52 PM.