Strange voltage reading

[Mertz]

I checked the voltage on my battery and it reads 6.39v. I’ve been playing with various electrical issues so I slow charged the battery overnight. I decided to checked the voltage while the engine is running. The amp meter is centered at idle and moves quite a bit to charge when accelerating. Generator rebuilt with new bearing and brushes. New voltage regulator. When set to 20v on the volt meter I was getting a flashing 19 so I moved it up one notch and same reading. Moved it up to 1000v got the same flashing reading.  Checked the voltage at the generator and voltage regulator and got the same thing.  Put the engine on high idle and turned on the headlights hoping they would not burn out. They didn’t and were just as bright when I turned off the engine.
 

Is this just the voltage regulator working, turning on and off the  charge?

[Plymouthy Adams]

something tells me you are having issues with your meter and or other selector switch or probe position......be sure you are position you probes into the correct hole for measurements you are wishing to make.  

[Mertz]

It reads perfectly with the engine off. I’ve been using it for a couple of weeks now on other issues like checking wire connections with the ohm meter and checking voltage to gauges. I will try another meter that is brand new. 

[Dave72dt]

You didn't say what terminals you were checking.  Most of these VOM's can't read fast enough for a signal that's turning on and off to stabilize.

[Mertz]

I checked the terminals on the battery, 2 terminals on the generator, battery to both other terminals on the voltage regulator.  I thought maybe it was the voltage regulator kicking on and off but am not sure. Since there is no over voltage at the lights I thought that might be the issue. It was blinking very fast and hard to read. 

[Sniper]

Try a new battery in the meter

 

If that doesn't clear it up, tell us what the readings are with the switch in AC.

[Mertz]

Good point about the AC setting. Battery is good but I will try other meters I have. 

[Plymouthy Adams]

if you do not have the users manual for your meter, often they are located online and easy to download.  

[9 foot box]

   It sounds like the field is grounded. The VR should be for positive ground, what is the part number?

[Mertz]

I’ll do these tests and let you know. Did the same thing on AC setting. I did polarize  at the regulator to make sure it was polarized. If I had a battery in my Studebaker I would see if it does the same thing when running. 

Edited August 31 by Mertz

[Mertz]

Tests showed no charge at high idle for both tests. Can you send page 84 to test the VR?  It is a new 6v unit but might not be the right one. 
 

I was just ready about test my VR and it appears the body of the VR needs to be grounded. Mine is attached to a board mounted to the firewall because the bolt pattern of the regulator didn’t match the holes in the firewall. I’ll try grounding it. 
 

Grounded it and it slowed down a little but still going over 20v. Flashing on all settings on two different meters. 

Edited August 31 by Mertz
Additional information

[Mertz]

I found these instructions for a new voltage regulator tucked in my motors manual which seems to contradict the removal of the field from the regulator. 

[Mertz]

I took the cover off the voltage regulator and didn’t see any movement in the contacts and the generator got very hot. There was a steady magnetic pull on all coils. The volt meter went crazy with only one lead connected to bat and gen. I believe the fault is in the regulator. Is this supposed to be an autolite regulator?  What should the amperage be?  I can get a VRR-4003A on line. Would that work?  What is the correct unit for my truck?

[denmopar]

Did you check for leakage (arcing) from the secondary (high-voltage) portion of your ignition?

Digital meters can be very sensitive to having HV arcs nearby.

Look for arc tracks in your distributor cap or meter leads in proximity to coil/sparkplug wires.

Worth the look?- Good luck with it.

[Mertz]

Good point I did hear that type of noise when I turned the engine off.  It lasted quite a while but didn’t find the source. All new wires and it starts and runs fine. 

[Sniper]

45 minutes ago, Mertz said:

Good point I did hear that type of noise when I turned the engine off.  It lasted quite a while but didn’t find the source. All new wires and it starts and runs fine. 

 

Unless you heard it in the radio while it was running whatever you heard wasn't the plugs or wires, especially after you turned it off.

Edited September 2 by Sniper

[Mertz]

I used the original wire from the coil to the base of the distributor and ran it through my plug wire holder. I rebuilt the wire and tired to start the car but it wouldn’t start because I forgot to put the cap back on and flooded it. Waiting now to let it dry out. I used a 16 ga wire. 
 

I thought the noise could have been the regulator. It probably was just the engine cooling down. 
 

When I tap the battery coil I get a little spark. With the engine running it stays closed. I’m looking for a new VR. 

[Mertz]

I have a GGW-6001A generator.  Does anyone know the correct part number for the voltage regulator for my generator? My Motors manual lists a lot of regulators but doesn’t link them to a particular generator. Is it that important and are the ones sold by our venders universal?

[9 foot box]

   If you Google “T137 Autolite cross reference” it might help you decide which VR you need.

[Mertz]

I found a cross reference and I bought a VRP4503B regulator. Hope it works.

[Sam Buchanan]

You're going to need to find out why you aren't seeing battery voltage at the regulator BAT terminal................

[Mertz]

I’m seeing voltage but can’t read it because the meter doesn’t read right when it’s running. I do get a voltage reading with the engine off. New voltage regulator will be here this week. 

[Sam Buchanan]

My bad....I got your thread mixed up in my head with another thread that is also discussing charging problems.

[kencombs]

Just a comment about strange readings with even quality tools.   I have an Fluke, expensive volt ohm meter that is fully automatic.  No selector, dial or any thing, Just turn it on and touch the leads to the conductors and it will sense either voltage or ohms selection and ACvsDC.   Except, I was using it to check out some trailer wiring.   Hooked it up with alligator clips, went to the vehicle and turned the turn signal on.   Meter read 6v, on a 12v system.   It saw the pulsing DC as and AC application and averaged the voltage, on/off times.

[Sniper]

Yeah, I have at least three different Flukes, well 4 if you count the Fluke O'scope as a meter, it'll do that.  I have never seen the issues the OP is seeing and without being there I cannot cogently comment on why it is.  I have seen the meters not read hz very well, but the O'scope does.