1941 buick charging issues

Hey guys, I could use some help here..... New rebuilt generator and voltage regulator but my battery won't hold a charge . Ammeter is showing a discharge when I do get it running and attempt to use headlights , radio, etc..but the battery is dying down quickly. I'm at a loss. Could it be just a severely dying battery that needs to be replaced or something else?

Does the charge rate increase as you rev up the engine slightly? If so, the charging system is likely working properly. Though it work be a good idea to check all of your connections, battery, ground, regulator, even the ammeter can have a bad connection and affect the charging. Be sure to disconnect the battery cable before messing with some the wiring, so you don't short something out. Also, does the car still have its' original wiring? If so, that could be an issue too, as most cars of that era with the old wiring have usually have many issues by now.

Hope this helps.

Keith

Swap out the battery with a known good one and see if it changes...

Do as Mark Shaw says above. Once you have a known good battery installed, start the engine and run at fast idle for 5 minutes. The charge rate should start high and then taper back toward zero. If you turn the headlights on the ammeter may show discharge at idle, but once you rev the engine it should move to the charge side.

Always wise to check all connections and grounds.

Let us know how it turns out.

Joe, BCA 33493

Did you polarize that rebuilt generator

john Hanson

I had a similar problem with my '39 several years ago. The generator had been rebuilt, but was still not charging correctly. The charge meter on the dash will only show about 7 amps, plus or minus. After many hours, I took the generator to a rebuilder, (local), and at first he all was OK. I said no, it was not. Turns out that the armature had a short in it that allowed some charge, but not the full 30-33 amps that it should be capable. The fellow who did the testing and subsequent new armature said in many years of this work, it was the first armature that he had seen fail in this manner. Most armatures show indications like melted solder and so forth when they die.

Just my experiences, hope they help someone.

Gary

A testing sequence you can try would be:

Charge your battery for about 1 hour at a maximum of 10 amps.

Test the voltage with probes into the battery posts.

Test the voltage with probes on the terminals.

Test the voltage from the positive post to the generator ground.

Test the voltage from the positive terminal to the generator ground.

All should be the same and read about 6 volts.

With the engine off, turn on the headlights for about 3 minutes.

Wait a minute after turning the lights off and check voltage post to post; should be about 6 volts. Less than 5 V. replace the battery.

Start the engine and check post to post then terminal to terminal. It should be about 7 volts or more, not over 8.

Turn on the lights. The voltage should not change.

Without writing a book, that should guide you too a bad battery, corroded terminals, or non-charging condition.

Since you have a new generator and regulator that have been polarized, the battery and terminals are straightforward. If it is not charging, disconnect the battery and check continuity of the generator to regulator wire, the generator ARM to regulator wire, the generator FLD to regulator wire, and the generator GND to regulator GND wire. If they all have continuity have a talk with the provider of the new parts.

OR put you findings and thoughts here.

Bernie

Thank you for all of the information/help guys. I'm going to start with a new battery, but unfortunately I have to wait til tomorrow when everything opens and I can go buy one. The ammeter is only showing a discharge as of right now. I've been charging the battery for approximately 1 hour and the car starts right up. The ammeter is not showing a charge, or discharge at this point. However, if I go to turn on the headlights, radio, etc. I'm showing a discharge. When we rev the engine, I'm not showing any type of charge, whether it be on the ammeter, or headlights getting brighter, interior lights getting brighter, etc. If I go to disconnect the battery while its running, it turns right now. I've been told that if it is charging correctly, you can remove the battery and it will carry itself.

We did polarize the generator once we installed it as per an "A circuit" system (armature to the battery). It "sounds" like the generator is running..if that makes any sense.

It is a new wiring harness from Wiring Harnesses Unlimited (let me tell you what a beautiful job they did). I completely restored the interior (hampton coach interior, rewoodgrained, engine turning, etc.) I'm hoping to get it on the road a bit before the snow flies up here in northern Pennsylvania and they put down the mass amounts of salt on the roads.

I'll keep everyone posted as this gets cleared up. Thank you greatly for the replies guys!

Just a quick update. New battery put in the car and still not charging. Going to test the voltage regulator next (It was bought NOS last year....but its still 70+ years old.) Also going to put a grounding wire from the body to the frame. I've had grounding issues with the car in the past. Fingers crossed.....

The quick check I used to do is to ground the field terminal of the regulator, and if it then charges, the issue is with the regulator, if it still doesn't charge, likely it is the generator. Check with a manual if this is a valid procedure with these cars, but I'm pretty sure it is.

If the car sits quite a bit (like most of them) it could be a sticking brush in the generator, and sometimes a quick rap on the side will jar the back into contact with the armature.

Keith

Grounding the field terminal on the regulator and runnign at a fast idle is a good check to see if the regulator is the problem or not as suggested by Buicknutty. I would not disconnect the battery while the engine is running as the battery does help stabilize the voltage in the system.

Joe, BCA 33493

You could try the tests I suggested.

Bernie

Ok guys, the weather seems to finally be enjoyable and car season is on its way. Im still having trouble with the charging issues. The battery is good, rebuilt tested generator and a modern 6 volt regulator. The cars wiring harness is also brand nee. The only thing we can think of is bad grounding throughout the car. Any ideas or suggestions? There dont seem to be any groumdimg straps on the vehicle so I installed two, one from the starter to the firewall , and one from the starter to the frame. Still having issues. Remember the gauge is nor, al during idle, and dips to discharge if the lights , radio or anything is turned on. This is all while the car is idling. Revving the engine does not show any charging on the ammeter. If testing the battery while idling, and headlights on, there is a slow drain on the battery...approximately .01 volts per 15 seconds. While idling, lights and accessories off...its steady around 6.3 volts. Could the ammeter be faulty? Does it need to be driving to be charging? More grounding straps?

Hi. Have a '41 Super Coupe. Had electrical gremlins w mine for a long time. new battery, new regulator, had generator & starter checked, cleaned, rebushed. Rewired individual wires for starting and charging system as well as coil...used mostly 8g & 10g wire. Seems to have taken care of the gremlins; have had trouble free starting/driving for six months/800m. Planning to drive to Portland from NorCal in July.

Good luck.

vr

Bob

I had a charging problem a while ago. I jumped through the usual hoops to no avail. I had converted my '38 Roadmaster to a later 6v generator and regulator that had more amperage outout. It worked fine for a long time. Then it went south. To make a long story short, the problem turned out to be that the regulator wasnt properly grounded. The regulator needs a good ground. Why it worked for such a long time, i dont know. Just cleaning things up for a good regulator ground and everything was OK again.

I had a charging problem a while ago. I jumped through the usual hoops to no avail. I had converted my '38 Roadmaster to a later 6v generator and regulator that had more amperage outout. It worked fine for a long time. Then it went south. To make a long story short, the problem turned out to be that the regulator wasnt properly grounded. The regulator needs a good ground. Why it worked for such a long time, i dont know. Just cleaning things up for a good regulator ground and everything was OK again.

Don,

Forgive a simplistic sounding response, but maybe the ground was"good enough" when the upgrade was first installed and for a "long time' afterward, but deteriorated later on due to atmospheric conditions (moisture creating minor corrosion in grounding contact), vibration, or those little gremlins which seem to plague us all at one time or another. Apparently just mounting it established a "good enough" ground at first, but even mounting screws can develop a bit of corrosion and create electrical resistance. Same idea as hoping that your trailer lights and brakes will work well when the only ground is through the trailer ball, and not a separate heavy duty ground wire.

Anyway, glad you improved it and have it working well now. Diagnosing these electrical gremlins can be frustrating, to say the least.

Marty. you hit the nail on the head. Time and moisture got it

We all know this, but as a reminder:

It is always a good idea to use a "Dedicated" grounding wire in addition to mounting a device to the grounded surface.

Maybe I should take my own advice because sometimes I do take the "quick and easy" way.

Sometimes the "extra" ground cable between battery and chassis, or between chassis and body, or between engine and chassis are inadvertently left off.

That is where gremlins creep in.

Sometimes a restored part is beautifully painted, interrupting an absolute (didn't want to say "positive" because some are "negative") ground.

Heavy stranded "000" cable is a good choice for these major ground cables, but for accessories you could generally use a wire as heavy as for the requirement as the device's power lead.

Remember that soldering the wire to the connector is always preferable to crimping for an absolute connection with less chance of corrosion between wire and connector, and a bit of sanding, grinding, or wire brush will enhance the connection electrolytic enhancing grease.