Gauge install-Voltage meter

Recently installed a Volt Gauge in my 96 Roadmaster. The install was pretty easy as far as the wiring,however
I dont believe that I am getting accurate data. The gauge wiring is pretty straight forward,one wire to a ground and the other
to a + or hot wire,the Stewart Warner instructions say the + should go to the ignition switch wire. OK so I have the gauge wired up and this is what
I get.When the engine starts it comes up to 11 or so volts and within a few minutes gets to 12 volts but no higher. When I put
my Simpson meter on the battery posts with the engine running I get about 14 volts. I cant attach my in car gauge to the battery
post or alternator post because the gauge would be working or "on" all the time.So is there a recomended place to attach the + wire for the gauge
so I can actually see how many volts the battery is getting from the alternator? Thanks , "under voltaged" ed

Did u try that gauge right from the battery to verify it also reads 14 volts? Might be the gauge

why are you obsessed with your charging system? for some reason you seem to be the only guy worried about the rpm/output of your alternator,.if the car starts in the morning, it,s working fine.
by your own admission you are an engineer,.perhaps asking the same questions on an electrical specific forum might help you get the answer you are looking for,
good luck,..


If you wire the volt guage to the alternator hot wire,. it'll indicate charging voltage,.yes the guage will be 'on' all the time,. but the power draw is miniscule,(about the same as a clock) perhaps an ammeter might be more to your needs,.

Nick

Sprocket wrote:

Did u try that gauge right from the battery to verify it also reads 14 volts? Might be the gauge

If the gauge across the battery reads something different than the voltmeter across the battery, there is no way to know which is wrong. You'll have to get a calibrated volt meter to use as a standard. Or a known-good power source.

Nick Danger wrote:

Sprocket wrote:

Did u try that gauge right from the battery to verify it also reads 14 volts? Might be the gauge

If the gauge across the battery reads something different than the voltmeter across the battery, there is no way to know which is wrong. You'll have to get a calibrated volt meter to use as a standard. Or a known-good power source.

Thanks everyone for your insight, I am going to try a few tests tomorrow. I will let you know the results. ed

Are you having a problem with your charging system?Just curious because normally its either
working properly or its broke,no inbetween?
Jim

Flasheroo wrote:

Are you having a problem with your charging system?Just curious because normally its either
working properly or its broke,no inbetween?
Jim

Hi Jim, No real problems with the charging system,I have a newly rebuilt alternator that I want to install and
I figured I would add a volt meter to the system so that I could see if it was charging properly. ed

Hey I don't blame you at all. I hate idiot lights. It's nice to be able to SEE what your car is doing....including the charging system.

[quote="81X11"]Hey I don't blame you at all. I hate idiot lights. It's nice to be able to SEE what your car is doing....including the charging system. [/quote

For early Feb. in Penna. it was a pretty nice day,so outside to the Roady ,the first change that I wanted to make to the volt gauge was to
improve the ground wire,what I had previously done was to use a t tap connector and attach the volt gauge ground to a rather small 18# wire
that was located under the dash. I removed the initial set up and ran an individual wire to a threaded stud located near the heat duct on the pass side.
With the better ground the gauge started reading a little higher. So, I am not where I wanted to be,but its definately an improvement.With the car driving
down the road anywhere between 1000-1500 RPM's the gauge was showing a reading of about 12.5 v. when I checked the voltage straight off the battery
with the Simpson meter,I got about 14.5 v at about 1000 RPM. So, for the present I am ok with the functioning of my" in car" volt gauge

The next bit of testing will be with the larger alternator pulley,so for all of you" charging system" fans stay tuned. thanks ed

I don't blame you either. If possible, i want all my gauges working as accurate (or, in the case of the oil gauge, as 'full sweep' as possible). My volt gauge reads about a volt too high, and after changing a resistor for the oil pressure gauge, it reads a tad too high (reads full peg on summertime cold start up). So, the next time I go into the cluster I'm going to do a little more tweaking.