Generator/charging questions

[Worden18]

Hey fellas, I'm having issues with the charging system on my Meadowbrook (1951).

Generator has been rebuilt (pulled and tested again... it's working); and I just put in a brand new voltage regulator and STILL it is discharging.  My gauge is working and I also tested at the battery and confirmed what the gauge is showing me.  So I'm thinking the old wires need to be replaced?

I read online that I should run jumper wires in place of the originals from the generator to the voltage regulator (armature and field) and then test at the battery.  But...what about the battery terminal on the regulator?  Where does that run to?  The ammeter?  Any suggestions on what to do?  I can't drive the car or it'll kill the battery, been there done that. 

[keithb7]

Are you able to test your wires for contact to ground? Continuity? Two exposed wires touching each other? Measure amp output from generator? A multi-meter with DC amp clamp is a marvellous tool for diagnosing electrical problems. A basic digital multimeter will get you a lot of info too. Have you seen my clamp style MM featured in a couple of my videos? I bought this one below on Amazon. It works well. A must-have tool for me.

 

Yet, knowing how to use it properly, decipher what its telling you, and basic electrical theory must be learned. That doesn’t come with the tool. 
 

https://meters.uni-trend.com/product/ut211b/#Specifications

Edited January 23 by keithb7

[oldodge41]

The wiring diagram I looked at online does indeed show the BAT terminal wire goes to the ammeter.

[Ivan_B]

I assumed you've performed some troubleshooting before fixing the generator, etc.? What seems to be the problem, now? Is the battery continuously discharging while idling in the garage? Does the generator voltage rise when revving the engine? What kind of voltage are you getting (at the battery) at idle versus revving? Can you please provide a bit more information about the observed symptoms, besides the fact that the battery goes dead while driving?

I do not believe that the old wires, per se, would cause the battery to discharge... ?

[rallyace]

After the rebuild did you polarize the generator?

[Tom Skinner]

Worden18,

Reconnect the A and F terminals backwards, rebuilt generators sometimes change those locations/designations. Then it charges. 

always re-polarize your generator with a jumper wire at the VR. Don't ask me why just try it.

(When you believe in things you don't understand - you suffer - superstition is the way) Stevie Wonder

Tom

[Worden18]

9 hours ago, Ivan_B said:

I assumed you've performed some troubleshooting before fixing the generator, etc.? What seems to be the problem, now? Is the battery continuously discharging while idling in the garage? Does the generator voltage rise when revving the engine? What kind of voltage are you getting (at the battery) at idle versus revving? Can you please provide a bit more information about the observed symptoms, besides the fact that the battery goes dead while driving?

I do not believe that the old wires, per se, would cause the battery to discharge... ?

I probably didn't do enough troubleshooting.  It stays at 6.30v at idle and when revving.  Of course over time that voltage reading will drop as it discharges the battery.

At the moment I did find an issue with the field wire.  NO continuity from the generator to the VR.  That has to be the issue.  So that particular old wire is a problem.  In the next couple of days I will be making up new wires for both the field and armature.  

[Worden18]

8 hours ago, rallyace said:

After the rebuild did you polarize the generator?

Yes, I did repolarize ?

[Ivan_B]

16 minutes ago, Worden18 said:

It stays at 6.30v at idle and when revving.

That sounds like a bare battery, on its way out... I would check the voltage straight out of the generator, and go from there to see where it gets lost. Do you have the wiring diagram for your car? That really helps to take out the guessing work from your troubleshooting

As for no continuity, check if you have it with both meter leads on the same side of the single contact\connector. Some of my contacts have some kind of aged oxidation on them, so you don't always get a connection for the meter leads unless you scratch the contact or push the sharp point hard to the metal. Just make sure that the line is really broken, before you start taking things apart.

 

If you think that the line is really broken, try jumping it with a temporary wire, to see if it changes anything (a wiring diagram is really helpful, at this point, to make sure that you do not connect things that are not supposed to be connected).

Edited January 24 by Ivan_B

[Worden18]

2-2-24: okay fellas the Meadowbrook is back in business.  There were two problems:

1. The field wire had a break somewhere and was giving spotty continuity.

2. The voltage regulator was bad.  I had put a NEW one on and that was bad, which threw me off and forced me to learn a few things.

 

First thing I did was pull off the ground cable from the battery while the car was running.  It died.  That's a sign something is wrong with the charging system.

 

I tested the generator by first taking the belt off and then running a jumper from the armature post on the gen to the negative battery post.  The generator took off spinning, no issues there.

 

Then I tested the VR for ground by running a jumper from the regulator base to the ground on the battery while the car was running.  The ammeter did not show a charge so there was no grounding issues with the VR.

 

Then I bypassed the VR by running a jumper from the field terminal to a ground bolt on the back of the generator.   The ammeter showed full charge from the generator with the VR bypassed.  So the new VR was the issue (and of course the old one initially).

 

I ordered a new VR from eBay and got it today.  I reinstalled everything (each connection with a bit of dielectric grease) and then polarized the generator and fired up the car.  Immediately the ammeter went to charge as my battery was a tad low.  Test drove for an hour.  No issues.  Thanks for the help, encouragement, and advice everyone.  Much appreciated ?

 

 

Edited February 3 by Worden18