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Re: changing ammeter to voltmeter

Posted: Fri Jan 12, 2018 4:28 pm
by Kaegi
Jim100 wrote:Wont a voltmeter read 14 something if the system is charging and then 12 something if it is not charging?
jim
not necessarily. if driving down the road with lights and heat on high it probably wont read 14.2. the load will drag it down.

amp gauges forever. :lol:

Re: changing ammeter to voltmeter

Posted: Fri Jan 12, 2018 7:59 pm
by hmaynord
"if driving down the road with lights and heat on high it probably wont read 14.2. the load will drag it down."
only if the alternator is undersized.

And how does an ammeter deal with an over voltage situation?

Re: changing ammeter to voltmeter

Posted: Sat Jan 13, 2018 1:36 am
by Kaegi
hmaynord wrote:"if driving down the road with lights and heat on high it probably wont read 14.2. the load will drag it down."
only if the alternator is undersized.

And how does an ammeter deal with an over voltage situation?
never heard the term "over voltage situation". does that mean over charging? the amp gauge will read output of charging system. it will read discharge if not charging. the higher the reading the lower the voltage in battery and it will show more output as more demand is put on system. if battery is a bit low it will read a higher output then as you run engine it will gradually come back down to near zero out put as battery voltage comes back up. if the reg is not working and its over charging the amp gauge will show max output all the time. or the reg can be bad and not allow any charging so amp gauge will show discharge.

Re: changing ammeter to voltmeter

Posted: Sat Jan 13, 2018 6:45 am
by hmaynord
OK. I agree the ammeter gives you better information. That just gets away from the point I’m trying to make.

As I’ve said, my goal is reliability. Here is my point: is that better information worth the costs? Those costs are (1) a longer charging circuit, which means some voltage loss when those amps reach the battery; and (2) more connections in that charging circuit, which means (a) more points of voltage loss, (b) when the alternator is outputting high amps, more points of heat generated, and (c) more points of possible failure.

So, for me, it’s an easy choice to go with the voltmeter, even though it will take me more time to realize the charging system has failed. That time is not critical, because I have the battery as a backup. It’s not the same as water temp and oil pressure, where I absolutely want to know those failures immediately.

I guess what I would like is a voltmeter that swings 90 degrees between 10 and 16, rather than 8-18. Then, a failure would be more obvious. I’d just have to get used to continual small movements of the needle being normal.

Re: changing ammeter to voltmeter

Posted: Sat Jan 13, 2018 7:35 am
by Jim100
My truck has a aftermarket wire harness. Painless maybe I cant recall what the guy said. The ammeter was done away with. physically removed.
Is it very difficult to wire in an aftermarket (maybe digital ) ammeter? I have a digital voltmeter in the dash which was easy but from what I gather a ammeter would be nice.
jim

Re: changing ammeter to voltmeter

Posted: Sat Jan 13, 2018 10:10 am
by marklein
Both monitor the charging system, if your alternator quits, the ammeter shows discharge, the voltmeter shows battery voltage. Imo, neither is better or worse, just the voltmeter has so many less inherent problems that ammeters are no longer used. If your charging system is in good condition, accessories should not pull voltage below where the regulator is set for more than a few seconds, if it can't keep up, it's either too small an alternator, or there's connection issues. If you have an overcharging situation, your ammeter goes over a certain amount, not specific, not telling you how much, a voltmeter may read 18 volts, way too high, I'd rather have the voltmeter myself.

Re: changing ammeter to voltmeter

Posted: Sat Jan 13, 2018 11:05 am
by PwrWgnDrvr
hmaynord wrote:OK. I agree the ammeter gives you better information. That just gets away from the point I’m trying to make.

As I’ve said, my goal is reliability. Here is my point: is that better information worth the costs? Those costs are (1) a longer charging circuit, which means some voltage loss when those amps reach the battery; and (2) more connections in that charging circuit, which means (a) more points of voltage loss, (b) when the alternator is outputting high amps, more points of heat generated, and (c) more points of possible failure.

So, for me, it’s an easy choice to go with the voltmeter, even though it will take me more time to realize the charging system has failed. That time is not critical, because I have the battery as a backup. It’s not the same as water temp and oil pressure, where I absolutely want to know those failures immediately.

I guess what I would like is a voltmeter that swings 90 degrees between 10 and 16, rather than 8-18. Then, a failure would be more obvious. I’d just have to get used to continual small movements of the needle being normal.
The statement on costs is incorrect.
1. The longer charging circuit is irrelevant if the wire is sized correctly.
2. Proper connections add negligible resistance to a circuit which causes negligible voltage loss and heat generation.
Even in a charging circuit with more resistance before the battery (longer piece of wire) the battery will fully charge. It only reduces the time for a full charge. IE, look at the puny (high resistance) wire used on the leads of a bench top battery charger.

With an ammeter, the gauge sits in the center on the 0 line. With a running engine in the daytime, no lights, fan, etc, a failed charging system will be visible immediately. Not so with a voltmeter. In fact, it is difficult to monitor charging with a voltmeter before its too late. U'll find out the next time u park and it won't start. Even an idiot light is better than a voltmeter for monitoring the charging system.
Been driving swepts daily for 40 yrs this coming April. NEVER had a an ammeter problem in ANY truck EVER!

42 WC63 6x6
59 D500 parts truck
61 D100 392 hemi project
62 W300
62 D400 dumper parts truck
63 D100 parts truck
63 D200 Crew Ute 413 NP420 parts truck
64 D100 Ute
64 D100 CSS Ute
65 D100 CSS Ute
66 D100 CTD NV4500 Daily Driver
66 D300 parts truck
66 W300 parts truck
66 W500
66 W500 parts truck
67 D200 CS parts truck
67 C500
67 D500 chassis/flatbed
68 D100 Adventure 383 727 parts truck
68 W200
68 D400 parts truck
69 D200 parts truck
69 D300 long chassis
69 W300 parts truck
69 D400 dumper
70 D100 parts truck
70 D200 CS parts truck
70 W100 383 NP445
70 W200 318 NP435
70 W200 383 NP435
70 W200 Crew 383 NP445 parts truck
70 W300 parts truck
70 W500 parts truck
71 D100 parts truck
71 D100 Adventurer
71 D200 CS
71 D200 CS Adventurer parts truck
71 W300 rock crawler project

Re: changing ammeter to voltmeter

Posted: Sat Jan 13, 2018 11:55 am
by Kaegi
all fears of amp gauges are irrational. fears fueled by baby boomers in the 70s who grew up on dummy lights and weed and dont know how to read one. ;/)
Even if I built a whole new custom system for a hotrod I would put an amp gauge in. you can even get the shunt type that do not run the charge wire through the dash. charge wire on those runs to a shunt block then 2 small wires run to the gauge. those are common in boats and equipment where the gauge is many feet away from the engine compartment.

Re: changing ammeter to voltmeter

Posted: Sat Jan 13, 2018 12:30 pm
by Hobcobble
Kaegi wrote:all fears of amp gauges are irrational. fears fueled by baby boomers in the 70s who grew up on dummy lights and weed and dont know how to read one. ;/)
I guess they were too amped up.... :thinking :joker

John

Re: changing ammeter to voltmeter

Posted: Sat Jan 13, 2018 12:43 pm
by Jim100
So ammeter is more precise. One can probably get by with a voltmeter but be aware that you can be misled under higher load?
Ammeters have lost favor because they require exacting correct installation ?
Do it right and you have a better gauge in the ammeter is the take home?
Or is this one of those things that has its camps and there is agreement to disagree.

I want the best gauge to let me know that yet another voltage regulator has failed and that I have what's left in my battery to get home or near a parts store!
jim

Re: changing ammeter to voltmeter

Posted: Sat Jan 13, 2018 12:44 pm
by marklein
If you have a failing charging system, it doesn't matter which gauge you have, it will still fail. You can buy an adjustable regulator, more expensive, but the way to go.

Re: changing ammeter to voltmeter

Posted: Sat Jan 13, 2018 2:51 pm
by 712edf
Option #3 is to get rid of your distributor ignition system & run a magneto. Crazy, but I've done it, makes the charging system less critical. :lol:

Bucky

Re: changing ammeter to voltmeter

Posted: Sat Jan 13, 2018 3:27 pm
by PwrWgnDrvr
Jim100 wrote:So ammeter is more precise. One can probably get by with a voltmeter but be aware that you can be misled under higher load?
Ammeters have lost favor because they require exacting correct installation ?
Do it right and you have a better gauge in the ammeter is the take home?
Or is this one of those things that has its camps and there is agreement to disagree.

I want the best gauge to let me know that yet another voltage regulator has failed and that I have what's left in my battery to get home or near a parts store!
jim
The only gauge that can tell u instantly the VR or ALT has failed is the ammeter. A fully charged battery will still read 14 volts for a period of time after the failure of the charging system.

Yes, do it right and u have more precise info with the ammeter.
The only problem is when people overload the system with more demand than it is designed for(foglights, steroes, etc). That's the same reason you get regional blackouts on hot summer days or houses burn down when ignorant fools install larger amp circuit breakers than the circuit wiring is rated for.

Re: changing ammeter to voltmeter

Posted: Sat Jan 13, 2018 4:14 pm
by Jim100
If anyone has a link to the easiest/ best step for step, or would be willing to describe the process for adding a aftermarket ammeter that would be great!?
Ill try google as well. and get a better voltage regulator.
And apologize for hijacking this thread!
jim

Re: changing ammeter to voltmeter

Posted: Sat Jan 13, 2018 4:54 pm
by marklein
Max on a 12v battery is 12.8, anything you read over that is surface voltage.

Re: changing ammeter to voltmeter

Posted: Sun Jan 14, 2018 8:24 am
by hmaynord
man day! I think I'll just go back to a dummy light! :withstupid :lol: :lol:
Thanks for the discussion. I've learned a few things.

Re: changing ammeter to voltmeter

Posted: Sun May 27, 2018 6:40 am
by hmaynord
for those of y'all who don't drink the ammeter kool-aid :lol: , I'll report results of installing a regular aftermarket voltmeter in place of the factory ammeter. Go to the end for the final result.

the voltmeter:
https://www.dropbox.com/s/azmjlxzba4hdc ... e.jpg?dl=0

approximate part of gauge that would be visible through the existing faceplate:
https://www.dropbox.com/s/wzjavwta280to ... n.jpg?dl=0

the preliminary plan:
https://www.dropbox.com/s/opqk9geu9tpxt ... w.jpg?dl=0

the hole, trying to center the gauge with straight-on view:
https://www.dropbox.com/s/k96k9zrwmjd5f ... 9.jpg?dl=0

installed, back: jb weld that looks like it's done by a 3-year-old:
https://www.dropbox.com/s/wsb058k0xbs8c ... y.jpg?dl=0

installed, back: must file down housing for instrument illumination bulb to fit:
https://www.dropbox.com/s/r8uo539oug8of ... 9.jpg?dl=0

installed, back: hole could be moved closer to fuel gauge:
https://www.dropbox.com/s/n3ynnh5k58zi7 ... y.jpg?dl=0

installed, back: note black foam rubber "mask" between glass and faceplate:
https://www.dropbox.com/s/0llrlom202t2u ... y.jpg?dl=0

installed, front, night: need mask because voltmeter illumination light "bleeds" around face of gauge and is really annoying at night -- it was worse than this without any mask at all; maybe moving hole closer to fuel gauge would get rid of this:
https://www.dropbox.com/s/quuhmkhn7johq ... t.JPG?dl=0

installed, front, night: from the driver's viewpoint, with the mask in place, I do not see any light bleed:
https://www.dropbox.com/s/ick03xwm54qht ... t.JPG?dl=0

installed, front, day:
https://www.dropbox.com/s/muc61y2ochh6p ... y.jpg?dl=0

installed, front, day: mask could be more symmetrical, but good enough for now:
https://www.dropbox.com/s/nb6gqb95ahdwb ... y.jpg?dl=0

my skills are extremely limited, compared with most of y'all around here, but it gives you the idea.

Re: changing ammeter to voltmeter

Posted: Mon Jun 25, 2018 10:11 pm
by welderseries
Good thread!

I just installed a Ron Francis kit as well. Decided to go with a GM one wire alternator, and the fella helping with my wiring ran a dummy light tucked into the cluster. We left the ammeter in place but just disconnected it.

Pwrwgndrvr, you said you've never had an ammeter problem in your impressive list of trucks... just wondering how many charging issues you've had?

Re: changing ammeter to voltmeter

Posted: Mon Jun 25, 2018 11:49 pm
by hmaynord
nothing beats a light for instant notification

Re: changing ammeter to voltmeter

Posted: Tue Jun 26, 2018 9:51 am
by PwrWgnDrvr
welderseries wrote:
Mon Jun 25, 2018 10:11 pm
Good thread!

I just installed a Ron Francis kit as well. Decided to go with a GM one wire alternator, and the fella helping with my wiring ran a dummy light tucked into the cluster. We left the ammeter in place but just disconnected it.

Pwrwgndrvr, you said you've never had an ammeter problem in your impressive list of trucks... just wondering how many charging issues you've had?
A dozen burned out alternators and regulators over the last 40 yrs. All diagnosed when the ammeter needle stayed on the left edge of the center line rather than the right.