VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Charging problems

Hi Everyone,

Working on the '50 and not having much luck so far. I've checked connections and got a new battery with a good charge in it. I used a jumper wire from the battery+ terminal to the A terminal on the generator, it turned like a motor (I did have the belt off). The I figured maybe I needed to polarize the generator as the car has been sitting 30+ years. It didn't change a thing, still not charging. I used my digital voltmeter and did show a slight charge coming off the generator, less than a volt though. I had noticed when I had the generator spinning it did make some noise. I figured that I needed to have it taken apart and cleaned up at least. I took it to the local starter shop and they put it on the test bench, I put out 30+ amps and 6.5 volts. So I guess that the generator is ok, but I am having it taken apart and cleaned up and probably a new set of brushes anyway. I've taken the cover off the regulator and checked to make sure that the points were not stuck or corroded. Everything nice and shiny clean inside regulator. I'm wondering what I need to do once I get the generator back and installed? Do I need to polarize it again? The way I understand it to polarize I need to jumper the G terminal with the B terminal on the regulator. So, looking for advise what to do next.

Thanks

Every time the generator is removed and reinstalled it must be polarized. You can polarize the generator as you described in your posting. Make sure the ignition is off and all wires are hooked up. If your generator still doesn't charge then you will need to look at the voltage regulator. Check your shop manual for details on how to test the regulator to see if it is defective.

:) :grin:

Thanks Junkyard Dog, I've been reading my shop manual and I can't find anything about how to full field the regulator. It is probably in section 12 but I'm not getting it.

Thanks

Touch the field wire to ground and that will full field the generator. Increase engine speed and if there is no charge the generator is defective. If there is a charge then your regulator has a problem.

:) :grin:

So I take the field wire off the regulator and ground it? Or the field wire on the generator?

Thanks

Take the field wire off the regulator.

:) :grin:

Hello Junkyard Dog,

You mentioned that you need to "polarize" the generator each time it is removed and reinstalled. Does that also mean you need to "polarize" each time the battery is disconnected and re-connected ?
My car battery is always disconnected when the car sits a couple of weeks, and I'm sure other owners may disconnect their batteries if their cars sit also.

I've never "polarized" the generator in 8 years since I've owned it and another friend has never done this in 20 years, except the time he had his generator re-built, then re-installed.Then again, perhaps that is why i've never got more than 2 years out of a battery.

No, you don't have to polarize the generator each time the battery is disconnected.

:) :grin:

Ok thanks junkyard dog, it seems like a lot of differing information out there.

The article below is what confused me: http://www.starautoelectric.com/Technical.htm

It states that whenever the battery is disconnected the generator needs to be polarized. Other articles I found online state that you only need to poarize if the regulator or generator is repaired, tested or replaced.It didn't make sense to me to do this each time you disconnect the battery.
Here is an article I found online for testing a generator, worth printing out as guide for anyone interested. http://www.nls.net/mp/volks/htm/gen.htm

Ya, they are saying that the generator "should" be polarized each time the battery is disconnected, but in reality, that is really not necessary.

:) :grin:

Hey I got a bright idea JYD. Why don't you explain exactly what the principle is behind polarizing the generator, then all of those guys that are new to electrical work can fully understand the how and why of the task.
Denny Graham
Sandwich, IL

Total agreement with the above. I have a "Green cable end" I disconnect the battery every time the car is parked in the garage. No need to repolarize every time.

I got the generator put back on. Ended up having new brushes put in and also replaced the front bearing. I put it on the car, I went ahead and polorized it even though the starter shop said I didn't need to because they did it when they put it on the test bench. All hooked and and still not charging. I took the field wire off the regulator and grounded it. When full fielded it charged like it was supposed to. I check the field wire for continuity and it was ok. I guess I have a regulator issue.
Whats the next step in checking out the regulator?

Thanks

That is incorrect. As mentioned earlier, the generator must be polarized each time it is removed and reinstalled on the car. Even though your generator was polarized on the starter shop's test bench, it still must be polarized again when you put it back on the car. So, by polarizing your generator when you installed it back on your car you did the right thing.

Sounds like you will need to invest in a new voltage regulator.

:) :grin:

I was reading in my service manual and it talks about setting the voltage and also adjusting the regulator. Can these operations be done without the tester that they refer to using in the manual? Or can I put my regulator on the bench and test it?

Thanks

For correct results I would use the proper test equipment. Even with the correct equipment, a voltage regulator is not an easy owner type repair.

In 1950 the station I worked at had a tune up shop (called the Battery shop still rebuilding them) any way there was one tune up guy that did all the VR work. He was very good at a touchy job. Others could do it but mostly all that kind of work was turned over to him.

what is the "proper" equipment to use?

I don't know what year you are working on, but for example the 1941 shop manual shows a Multimeter in use on page 26-4.

I have a multimeter unit from Craftsman that includes all the necessary test leads and a resistor to use during the load tests.

If you have a Motors Manual, of the early vintage, it also shows the step by step and shows the equipment needed.

I have been at this job for many years and I think I have mastered most cases, except, the early Pontiacs and Buicks, which used a two stage VR. The quickest way to handle one of those was to replace it with a normal single step VR. I took one car to the dealer to have the VR set and he said he did not have a qualified mechanic who could set it correctly.

Voltage regulators are not only tricky but hard to adjust for the post part. You would be a lot better off installing a new voltage regulator instead of trying to fix the old one.

:) :grin:

The adjustments set the charging rate only. If its not working either the contacts are dirty or there is a problem and replacement is necessary.

Replacement Voltage Regulators are not cheap, so be sure and check it carefully before ordering a new one. New ones are available from the Filling Station, Chevs of the 40s and other suppliers as well as local parts houses. I got one from NAPA about a year ago.

Hi Everyone,

The charging issues are solved. My '50 is charging just like it should. I ended up having the brushes in the generator replaced and also the front bearing. I did also purchase a new US built regulator. I cleaned all the connections also. It is charging at 7.4 volts. The battery is fully charged and the amps drop down at idle, when I put the headlights on the amps go up like they should to maintain the load. I ended up confirming the the regulator that was on the car when I got it was bad. The Delco regulator that I pulled off my '49 pick-up in the shed is good, just needed the points cleaned and then adjusted the cut-out relay and it worked good on the test bench. I'll put that back ont he pick-up so its complete when I'm ready to get it back on the road again. I ended up paying just over 70.00 for the new regulator.

Thanks for all the help
Don

Hello Guys,

Just following up from this post of a few weeks ago. I think I now have a charging problem. A few months ago I did a post on a battery problem I had. I managed to fully charge the battery with a charger. Also drove the car a few times in the last 2 months during the day with no starting problems, and it seemed ok. Last night I drove the car at night for the first time and with the headlights on the amp gauge dropped to the extreme left whilst idling in traffic, and the turn signals froze or didn't work properly. The gauge did move to the right again at acceleration. After turning the engine off in a service station I was unable to start car again, as it appears the lights drained the charge from the battery. Coping abuse from people at the station for holding up the fuel queue I managed to push the car to a corner.

As I had no jump leads I called the mobile service mechanic and he put a volmeter on the battery. It read 6.3 volts and said the battery was ok ? I have charged this battery on and off over the last 2 years. I then got a fast jump start and at medium throttle the generator is putting out about 6.3 volts approximately according to the voltmeter, and slightly lower with the lights on. He seemed to think this is too low, so do I as I thought the charge rate should be at least 7 volts or slightly more ?
I also haven't looked at the voltage regulator although it had been replaced and looks newish like only 9-10 years old (limited driving over the last 8). I do have a rebuilt 53-54 generator in a box. Do you think I should just replace the generator on the car or get a new battery or both ? Don't know how old the generator on the car is, it may have partially worn brushes etc.
I am also hoping the regulator insides hasn't arced or anything, as I didn't really want to buy another one.
Any advice would be appreciated.

The engne would have to run at a fast idle for about 20 minutes to get up to the 7 volts. If it does the charging system is working. Are you usig halogen bulbs in any of the lights?
A test of the generator would be to short out the field terminal while the engine is running at about 40 MPH....this should cause the dash ammeter to go way to full charge.
The battery really should be load tested. I assume that the cables are in good condition and are of the larger diameter that is required for a 6 V system.