[T3] Question on my 73 T-3 Square back . Charging system.

[Jim Adney]

There's a good chance that what you're seeing is perfectly normal. It's likely 
that you have your voltmeter wired to the fuse box, so you're seeing the IR 
voltage drop between the voltage regulator and the fuse box.

Since the voltage regulator is only able to control the voltage at the battery, 
you should consider running a dedicated sensing wire from the battery + 
terminal to the + terminal of your voltmeter (and remove the wire from the 
voltmeter to the fuse box.) This will give you a better picture of how your 
charging system is working.

Keep in mind that voltages taken at idle or with the engine off may tell you 
something about the battery, but they say nothing about the charging 
system, since the charging system isn't working then.

On 30 Jun 2018 at 23:27, William J wrote:

>  Tonight was the first time since 2006 I drove at night . With the head lights and tail on even at 2500 RPM the VDO voltage gauge was just at about 12.5 volts at least that's what it looked like since these gauges are not equal spaced marks and at idle it was below 12 volts. Now without the lights on at idle it's a bit above 12 volts and at 2500 RPM above 14 volts. 
> 
>  I only ask because it's been so long I forgot what it used to read. I did adjust it because it read low a while back and on VDO volt meters they provide an adjustment screw so I set it to match what my DVOM reads and it was steady and the same at all RPM's as the DVOM. As soon as I turned off the lights when I parked the car the volt meter came back to 14 volts. The interstate battery is less than a year old never went dead and reads 12.5 to 12.6 volts after the surface voltage drains off. 
> 
>  Does this sound normal ? The gen light never came on yet it does work . 

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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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