Charging problems

[John431]

Howdy ya'll

I'm have a charging "issue" here's  my story....my 47 club coupe not charging...I was getting erratic readings with multimeter (0-18v) with engine running, everything checks out fine with engine off

So I sent the ol'gen out for rebuild..reinstalled same issue...so I was told probably a bad V.R. ok...replaced that..same issue

(no charge, erratic voltage) so then I disconnected the V.R. started the engine, multimeter on the gen..."erratic" reading...all wiring checks out. The only thing I notice is the terminals at gen seem to be stamped in reverse and is I switch F and A field wire gets hot....my only thought is there is some kind of issue with the generator (unless I'm missing something) so I'm at a total loss any help/info would be much appreciated!

Thanks !

[greg g]

The generator terminals should be two different diameters.  Large for armature, small for field.  Did you do a polarization of the generator after the rebuild?  Did you clean the points in the VR??  Did you conduct the basic generator test??  Make a jumper wire from 10 or 12 gauge wire with an alligator clip at each end.  Start the engine set the idle to around 800 rpm.  Ground the field wire with the jumper wire.  The generator should let to full charge. If it does that indicates the Genny is ok, and the faultis in the VR.  Make sure the VR chassis is firmly attached and grounded and all your connections are clean and tight.

[John431]

Thank you for the info....I just tried grounding the field terminal..."nothing"

I'm assuming the problem lies in the gen...although the person that rebuilt it stated it was tested and worked fine....I also dont understand the "erratic" voltage only when engine is running (gen spinning) otherwise everything seems to check out, I'm starting to pull (what's left of it) my hair out with this...thanks again !

[PT81Jan]

Quote

 

I also had trouble with the charging system.

Also erratic reading at the multimeter, I felt really stupid at some point. I also thought it is the gen, but had its cause in the regulator adjustment.

What I first didn`t notice at the beginning and then underestimated was the polarization recommendation / requirement.

Got it adjusted and works now.

Anyway, here`s a video, which helped me a lot. Maybe it gives you or others also a better understanding of the charging system.

 

 

[John431]

Thank you for that information. I've been testing every method suggested  with no success....everything seems to lead back to the generator( in my opinion)...the thing that makes me think that it's the gen. Is all is fine and checks out until I start the engine..then i get the erratic voltage readings (rapid fluctuating 0-19v) with the multimeter..which occur at the battery, voltage regulator, and pretty much any other place I check.

With that ...I  assume its possibly the generator (it wasn't professionally rebuilt) I have replaced the V.R and polarized.

I appreciate any info, comments,

suggestions.

Thanks !!!

[Los_Control]

Just curious because do not know ... is there a way to remove wiring from genny and test it with multi meter with engine running ... isolate the genny from the wiring & car?

[Sam Buchanan]

Once you get tired of messing around with the antique generator and regulator there is a simple and final solution.  ?

 

https://www.ebay.com/str/HowardEnt?_trksid=p2047675.l2563

 

 

 

 

 

Edited July 24, 2020 by Sam Buchanan

[soth122003]

Something I noticed when going thru the same problems, was that the digital multimeter is so fast it can pick up all the changes in the voltage being carried by the genny the VR and battery charging system that it will fluxuate very fast and will seem to give very erratic readings. I had an old analog multi meter and when i started using that instead, I was able to get stable readings and trouble shooting went very smooth from there on out.

 

(just curious because do not know ... is there a way to remove wiring from genny and test it with multi meter with engine running ... isolate the genny from the wiring & car?)

 

Just disconnect the genny wiring and start the car. With it running check the voltage output at different RPMs. The genny's main job is to supply power to run electrical systems and charge the battery. with it disconnected it will provide power, but it will have nowhere to go until the wiring is re-connected.

Joe Lee

Edited July 24, 2020 by soth122003

[plymouthcranbrook]

I keep mumbling to myself about this one:

 

https://www.qualitypowerauto.com/item_24/6-Volt-Alternators-Positive-Ground.htm

[John431]

Hi, I want to thank everybody for all of the info/suggestions.

Giving thought to my "problem" I think im going with switching to the  alternator (less problems) i think I was "burned" on the gen rebulid... so dont i want to put more money into the gen with poss "average" results... I am also considering Pertronix ignition... I think that combo will result in better overall reliability.

Again Thanks everybody !!!!

[Los_Control]

Sounds like a good plan, I am kicking around the idea myself.

 

I would also consider going 12 volt and call it a upgrade for a driver, you can now use modern radio, brighter headlights, tail lights, gps ...

 

If you do a little research, you will find it is pretty simple to convert to 12 volt, change all light bulbs for sure, I think your gauges will work fine as is ... they are mechanical and gas gauge does not care.

Wiper motor if you have electric will need attention and same with heater motor. Both will work on 12 volts for awhile, just turn faster then 6 volt and eventually burn out and need replaced. But can run a 12 > 6 volt reducer to them. Radio is a problem.

 

I remember when I was a kid, the adults just switched to 12 volt because it was easier and cheaper.

Today we stick to 6 volt to stay stock.

If going alternator, is no longer stock so why not go better and cheaper? .... ya going to stick your toe in the water? Or just jump in?