The Stovebolt Site Forums The Shop Area The Electrical Bay charging problem

I have a '59 3800 that hasn't gotten driven a lot recently. Last fall it got called into service when I wrecked by daily driver. It developed an electrical problem; it wouldn't charge the battery and actually seemed to drain it. Lights wouldn't stay on and truck would run like crap with them on - turning heat or defrost on made it worse. I was busy in the middle of a big job (or 3), got frustrated, and put it back in the garage as soon as my daily driver got fixed. Never got back to it...

Until recently. I'd been advised that the voltage regulators regularly experienced problems - so I got one off ebay and put it on. Threw the trickle charger on it for about an hour then jump started the truck. Seems to run well - HOWEVER, the voltmeter goes all the way to D when you give it gas. At idle, its just on the D side of the middle. Turning on the lights, heat, defrost, and hazards makes the needle tend toward C at idle, but still goes to D with acceleration.

Thoughts? Ideas? I'm frustrated and the Shop Manual (I have both the manual for the 58 and the supplement for the 59) doesn't seem to be helpful.

plunkinberry,

Welcome to the Stovebolt. I'm not sure I can add more than the service manual does to help solve this problem. The charging system can be broken down into two basic components and if one is tested and proves to be good, then the other is usually the problem.

If you run the rig, put the generator into full field charge and your ammeter pegs to 'C' then the generator is off the list of suspects. This is done by pulling the field wire at the voltage regulator and momentarily touching it to a good ground.

I think buying a voltage regulator off of E-bay is sort of a pig-in-a-poke kind of deal...it could be toast but look fine. Although it usually isn't necessary to do this if the generator proper hasn't been disturbed, polarizing the system wouldn't hurt anything. Momentarily touch a small jumper between GEN (ARM) and BATT tabs on the voltage regulator.

If the battery is more than 4 years old, it could be headed off into the sunset. Check the water, clean the posts and give it a full, long charge.

You can easily check the fan belt tension and peek into the commutator area of the generator to make sure your brushes aren't 'stubs' and that the commutator isn't crusty jet black. The brush holders must not be hung up...they need to be shoving the brushes on the commutator.

Look at the wires on the generator for breaks and loose connections. The regulator grounds the field to make the generator charge so the F wire must not be broken anywhere as it heads to the regulator.

Try some of these things and let us know if you solve this problem.

Stuart

OK, I'll try some of this tonight or this weekend... I will start by pulling the field wire off the voltage regulator and touching it agains the cab - this should ground it, correct? And, I'll need someone to watch the ammeter at the same time? If it doesn't peg at C, then what?

The battery is old but I'm not sure how old. I took it out of my jeep a few years ago... but seems to be holding up well. I will check it and all the other connections as well, just to be sure.

I'll start there...

Thanks

plunkinberry,

The cab should be grounded...if it weren't then lots of other things wouldn't work. I'm a tad anal, so if the grounding of the field wire at the regulator end didn't make the generator hop to it, I would leave this wire loose and not touching anything, and do the same procedure at the generator using a jumper wire from F terminal to engine ground. This little drill removes any question that the F wire might be broken somewhere in its path to the regulator.

If these tests prove negative, it is telling you the generator cannot produce voltage. It will need to be operated on, or replaced.

If the full field test on the generator proves that it will function properly, then the voltage regulator comes into the spotlight. If it can't tell the generator to charge, it's defective.

The idea here is to prove the device you have the ability to test...the generator! Testing a voltage regulator is pretty tough for a amateur.

Stuart

The symptoms would indicate a need to polarize your generator. You can do it at the regulator.

plunkinberry,

If you ground the field and the generator still shows no charge on the ammeter, it isn't conclusive that it is the generator...it could still be the regulator. If you attach a small jumper from the A (Armature) tab on the regulator to the B (Batt) terminal, you bypass the current regulator and cut-out relay inside the regulator itself and connect the generator directly to the battery. If this test shows a charge on the ammeter while merely grounding the field wire showed NO charge, the regulator is defective.

Remember that with a generator, you must speed the engine up slightly to produce a charge.

Stuart

Thanks guys, I'll give these a try and report back in...

plunkinberry,
Everybody here is on the money,including atomarc I might add ,....
But you said that you put on an ebay Replacement Regulator.....
IF You did Not polarize the generator after this change,The Gen wont charge no matter what you do.
Regards,
Steve Sr.

OK... how do I polarize the Regulator? Guy that sold it to me on ebay took it off a running vehicle - it appears that he used the aftermarket one while he painted the vechicle cause its got overspray on it... Does that make any difference?

Plunkin,
take a pc of at least 12 gauage wire and jump from the positive terminal on your battery to the Field side of your generator to polarize it .
It will just take a second ..dont hold it on there ..you will see a spark an it is done ..ya dont need to polarize the regulator.Hope this helps .

To polarize the generator, momentarily touch a small wire from the GEN (ARM) terminal to the BATT terminal at the regulator. This procedure is done with the engine OFF.

Stuart

Hey Guys
I have a 53 GMC and I have been reading about the charging problems. I have tried everything mentioned. My gauge still sits just below the "D" side. It doesn't move even if I up the throttle or turn on the lights. I just cleaned all the connections to the regulator and still no luck. I tried doing the polarize but still nothing. I know it is not charging because if I run the truck for a half hour or so and then put a charger on it, it shows the battery to be really discharged. Is there some way of doing a check on the generator itself ?

Wolfs53,

Read the first couple of posts in this thread, it tells you how to check the generator itself. If you don't have any luck or need more confusing directions, it's best to start a new post on your troubles. Good luck and keep us posted.

Stuart

Wolfs53,

You must have more than one problem if the ammeter doesn't show a significant discharge when the headlights are on and the engine is off. Your truck was originally positive ground, have you switched it to negative ground?

Baldy,
Yes the truck was switched to negative ground when I bought it. I tried grounding the field wire off the voltage regulator to ground and right off the generator to ground but, I still don't get any movement in the guage. I have polerized the generator as well. At this point I am not sure the gauge is even working. I guess it's possible something wasn't completed properly during the conversion. It wouldn't be the first thing that wasn't done right. I have no idea where to go form here. Any help would be appreciated.

wolfs53,

Because the ammeter is in question, you will have to prove the generator 100% with some other instrument. A multimeter can be handy for this, and cheap too. Connected between ARM and ground using the DC scale should get you results. Ground the field wire again, and bring the engine RPM's up.

Worn brushes, weak or hung springs or a dirty commutator could be a problem with the generator. Has the system worked previously...did the ammeter read properly before. If the answers are NO, maybe the swap to negative ground wasn't completed properly.

If you can prove the generator, and the ammeter still doesn't respond, it might be the regulator. If you can get the generator to GEN, you can proceed from there. A small inexpensive meter is must have for these problems.

Stuart

I once heard that if you could make a motor from the generator,,its good. By connecting pos. to the armature connection,and neg. to the case?
Sound right?
Marty

Atomarc,

Real strange...started to test generator as you suggested and I think there was some voltage showing on the multimeter...then the engine quit.
I have tested everything I can think of but, I still can't get it to fire up again.
I did notice that there was a 6 volt coil in it. Is that right...it is now a 12 volt system....at least there is 12 volts going to the coil ?
I checked the 6 volt coil and replaced it with a 12 volt coil but still no spark. I'm lost...

Wolfs53,

Wow...the problems are breeding like roaches! Backtracking a touch, your truck has been converted 12 volt negative ground, but you are still using a generator, is this right?

I don't think the current problem is related to your charging problem. Not trying to insult your intelligence, but could you have run out of fuel.

Does the battery have sufficient charge to start and run the engine? Sometimes actually seeing a spark it tough! Your test has done nothing that would affect the spark or ability of the engine to run. The iron clad spark test would be to hold a plug wire near the engine while someone cranked the motor. A spark should be seen jumping at least 1/4" or so.

Did you actually see 12 volts on the key (+) side of the coil with your meter? Make sure you have fuel, the battery is charged and the key is on...try it again, it will go!

Stuart

Atomarc,

Yes, the truck has been converted to 12 volt negative ground and is running a generator.I did see 12 volts on the (+) side of the coil with the meter.

I have lots of gas,I can see it in the glass top on the fuel pump and in the carb when the throttle is pressed.

The battery is right up, I have a charger on it since the charging system is not working right.

I already removed a plug and held it to the engine while my wife cranked it over, no spark.

Seeing as though there is 12 volts going to the coil, shouldn't it be a 12 volt coil ? The one that is in the truck says 6 volts on it !

Wolfs53,

The difference between a 6 volt coil and a 12 volt coil (unless internally resisted) is minor. The points allow the coil to function, and the points and condenser don't like a full 12 volts for maximum life. In your troubleshooting to get this rig running, you can connect your voltmeter between coil - and ground, and as you crank the engine over with the key on, that voltage should toggle from 0 volts to some value near battery voltage.

Part of the swap to 12 volts should have included some method to reduce voltage to the coil...a ballast resistor, or a 12 volt coil that has resistance built in. This is something you can think about after you get it back on track.

If you want to prove your existing coil, you should be able to get the coil wire to zap when held NEAR a ground by turning the key on and alternately touching the primary lead wire, which is the small wire going to the distributor, to ground, then removing it. This action fires the coil. Don't give up.

Stuart

Okay Stuart....

Went out tonight, changed the spark plugs because I found one that was cracked. Looked closer and found that the wire going from the (-) side of the coil to the distributer was not in the best of shape. So, I made a new wire to replace it. Did the checks as you suggested and everything seemed okay. Turned the key on and hit the starter and it fired up !!!

However...it ran for about five minutes and quit for no reason. Waited about five minutes and it started again only to run for about one minute and then stopped. Can't get it to start again..

I can't seem to keep it running long enoungh to check the voltage from the generator, my original probem.

Could it be the coil heating up or may the condenser !!

Thanks for your patience

Dave

Dave,

Well it would appear it's either no spark or no fuel. When it fizzles out for the last time and you can't get it to go, you will have to see what 'isn't there...fuel or spark! When this happens, put your meter between coil - and a ground, then crank away! If you want to take the other route, when it happens, squirt a little fuel into the carburetor and see if it springs to life.

I can see no connection between your generator troubleshooting and this problem. I think it must be written off as coincidental. Your rig has a 12 volt battery and the negative is connected to ground... you have no doubts that the generator, regulator and other items were also swapped to 12 volt.

Coils and condensers can be sensitive to heat and fail when warm. It didn't sound like the engine ran long enough for things to get hot...if you have a 12 volt coil, it wouldn't take much to stick it on and erase any doubt you might have. The test I mentioned above with the meter on the primary lead wire would tell you if the coil was sound. Keep at it!

Stuart

Stuart

I did have some doubts if everything had actually been converted. The battery is 12 volts and the negative terminal goes to ground. The starter says it is 12 volts but, I don't see any markings on the generator or regulator.

I will try what you mentioned tonight. I'm not sure what I should see when I test the coil. When I put the meter on the (-) side of the coil and to ground and then turn the key on, there is a reading right away before I crank it over.

I really appreciate your help and patience.

Dave

Dave,

When you attach the meter between the coil - and ground, you should see the voltage fluctuate between zero volts and about 9 volts or so, as the points open and close. This should show you that the coil isn't open, and that the points are actuating as they should. I really wouldn't hurt to check the point gap while you're hanging out near the distributor.


Stuart

Hi Stuart

It's your pain in the butt Dave....

I got home tonight and tried a few things.

First, I cranked it over and it wouldn't start so I but some fuel down the carb. Still nothing..

Next, I tested the coil as you suggested. I put the meter between the (-) side of the coil and ground. As soon as we turned the key on I had a reading on the meter. It went down a slight bit as I cranked it over but never went anywere near 0. Next, I took the cap off and turned the engine until the points were open to the fullest. With the key off, I checked resitance between the wire that goes to the distributer and ground, got a reading. It seems to me that the coil is being grounded even if the points are open. That doesn't seem right to me, although when it comes to electrical, I am lost.

Should I replace coil, points, and condesor ?

If so, what should I ask for ?

I think it's a 1951 235....

Thanks Agaian.....Dave

Dave,

You are far from a PITB. I do this amateur Mr. Goodwrench stuff because I enjoy helping folks with the hobby...I wish I had all the right answers though.

I wouldn't replace anything right now. I would clean the points and gap them to maybe .017 or so. If you have a points file, use that, or a little piece of 600 grit sandpaper.

The test I described earlier was made using the DC volts scale on your meter. If you measure between coil - and ground, with the key on, you should read zero volts when the points are closed, as the potential has gone to ground, and you should see close to system voltage when the points are open...no ground available.

You can get lost when you start chasing continuity with the meter...stick with the DC volts scale for now. If you gap the points properly, and no wire is mashed or shorting inside the distributor, and the condenser hasn't suddenly decided to fail, your DC meter should read voltage with the key ON and the points OPEN when hooked from coil - to ground.

Stuart

Stuart

I went out this morning and checked the voltage on the coil as you said.

When I first did it, I had 12 volts on the (-) side of the coil with the points open or closed. So, I cleaned and gaped them as you suggested and for a brief moment I had no volts when the points were closed and 12 when open. Got my wife to crank it over and I seen the points spark as they opened and closed. I put the cap and rotor back on and tried it...nothing. I took the cap back off and I got 12 volts again both open and closed and no points spark when we crank it over.

Should I try to clean them some more or just get new points and condenser ?

Could the fact that there is 12 volts going to the points be a problem ?

What is the best method to reduce the voltage, an external resistor or one as part of the coil ?

Dave

Dave,

I'm not sure what is going on, but it would probably be easier now to do as you say and just install a new set of points and condenser. Putting a new coil on wouldn't hurt either. Because you don't have the bypass wiring in place, a internally resisted one would be much more simple to install. Std Motor Products OR Carquest coil # UC-15 would work fine.

I think new points gap between .018--.024! Give it a try and keep us posted. Good luck.

Stuart

Stuart

Changed coil to the one you said, points, and condesor....wooowhooo. She's alive...took it for a half hour run..all okay. You're great...thanks for your help.

Back to the charging problem....

Now that it runs...I did what you mentioned some time back. I put the field wire on the generator to ground and then checked for voltage from the gen wire to ground. I got 12 volts at idle and more as I increased the RPM. Sounds to me that the generator is working.

I guess at this point, It's the voltage regulator that is the problem ?

Any suggestions for a replacement ?

It's to bad your so far away...I would sure like to share a cold beverage with you....

Dave

Dave,

Congratulations. It does sound like the voltage regulator might be the culprit. I would make sure the wires from generator to VR are in perfect condition. A '55-'63 Chevy truck uses a 12 volt, negative ground regulator in the 25/30 amp output range. Standard Motor Products # VR-20 is the number for that regulator.

Be sure to follow the instructions with the regulator on polarizing the system. I'll drink an O'Doul's and toast your success.

Stuart

Dave,

I didn't mention this, but the voltage regulator must have a good ground to work properly. If there is any doubt, a small jumper can be installed from regulator to good, clean ground to see if this makes a difference.

Stuart

Stuart

I replaced the VR. The one that was on there was 6 volt. It seems like it's charging now. I get 12 volts at the battery and then it increases to just over 13 when the RPM's go up.

Sound right to you ?

The gauge still doesn't move on the dash though. I guess it's no good.

Thanks again for all your help.

Dave

Dave,

That sounds perfect. Find a new gauge and your back on track!

Stuart