1957 3100 - battery charging issues and questions

[hplacecf]

hi.

ultra old truck newbie here with battery charging questions (what appears to be lack of battery charging).


just got a 1957 3100 project truck in a state of 'it needs work...' some of the wiring has been cut. for example, none of the headlights or taillights work, but the dash light works.

it has a v8 engine that looks old (maybe original), though someone changed out some things on it like the carb and valve covers.


I never worked on anything that old before (I am more familiar with the 1970s and up).

I have never really dealt with electrical charging issues before.

here is my back story.

(1) the truck would not start unless jumped.

(2) it would then run a while (it is not registered, so I just ran it for 5-10 minutes in my driveway).

(3) once it was turned off, it would not start again.
(it would crank slow and then stopped cranking - like it had a dead battery).


if I jumped it again, or charged the battery, the same thing happened (2,3 above).

so, I got a new battery and battery cables and the same thing still happened (2,3 above).


made me think about the alternator. but searching, I think that maybe what I have is a generator and not an alternator? it is black and longer than any alternator I am used to seeing. only seems to have 2 small wires that looks like they join other wires going back to the dash.


questions:

how is the battery 'supposed to be' charged by the set up that I have?
since it appears that this is not happening.


what was there before I changed the wires and battery was:

(1) a single positive cable from the positive post of the battery to the starter.

(2) a single negative cable going from the negative post of the battery to a bolt on the firewall. when i changed that cable I attached it to the frame instead (as a result of the firewall bolt snapping off).

thanks in advance.

[_Ogre]

old truck wiring was minimal at best
you may have a ground issue; add a ground strap from the frame to the motor (for the starter) and one to the body (for lights and charging system)
the gm generator had to be polarized; usually only once, but sometimes everytime you disconnect the battery

basic gm charging circuit


interesting video on polarizing a delco generator
https://www.youtube.com/watch?v=7CRtUlgIgyU

[OrrieG]

Look at this post, myself and a lot of others gave schrum good detailed information on the system. Take a look and if you have more questions, ask away.

http://67-72chevytrucks.com/vboard/s...d.php?t=616924

[hplacecf]

thanks for the advice.
I tried it.
still no good, but there was hope for a few minutes there....


so,
in addition to the existing ground cable I had run from the negative post of the battery to the frame,

(1) I added a ground cable from that same point on the frame to the engine at the valve cover (not sure where else to attach it...).

(2) I added a ground cable from that same point on the frame to a bolt on a fender body panel.

I jump started the truck and it eventually started.

my volt meter with one point on the negative post of the battery and the other point on the positive post, showed it at around 12.18 and it started dropping slowly over time to about 12.06.

I tried 'polarizing the generator' by taking a wire from the positive post of the battery and touching the post on the generator that was not labeled 'f'. I got a little spark, like on the youtube videos, but still no good, number still around 12.06.


so, I next removed the ground on the body panel bolt and tried attaching it to another bolt. I immediately heard the engine sound different (maybe a little slower?). I hooked up the voltmeter and it showed the number climbing upwards (kind of jumping around) until I saw it jump at its highest to about 12.34.

I thought life was good, kept the engine running, and decided to come back later expecting the battery to be fully charged.

but, when I came back later and attached the voltmeter it was back to around 12.06 - in a bad way. I thought, huh? I checked all the wires and they were as before.

I turned off the truck and it would not start.

any ideas what might be going on?

what next?

thanks in advance.

[_Ogre]

are you cleaning the paint/rust/greasy gunk off the area around the ground bolt or just attaching the ground strap?
generators typically don't charge well at idle they need higher rpm's to charge
easy thing to do is throw a 1 wire alternator on it
but even that won't fix bad wiring connections

[Highsider]

Is it premature to blame it on a faulty starter, after all of the above has been done?
Last summer I had "heat related" starting issues and a new $36.00 O'Reilly's starter cured it.

[hplacecf]

Originally Posted by _Ogre

are you cleaning the paint/rust/greasy gunk off the area around the ground bolt or just attaching the ground strap?

I sanded off the paint on the body panel so it was bare metal of the body panel to bare metal of the ground cable end. again, once I did that, the battery number started to climb (whereas before I did that it was a steady low number), at least for a while, so I 'think' it is a good ground (or was for a while).

is there a way to tell if a ground is actually 'good'? other than seeing if my issue goes away.


Any other ideas?

thanks in advance

[hplacecf]

another question,

how does the charging 'from the generator' get 'to the battery' to keep it charged? never really thought about it before. I wonder if something is not connected, or is broken/faulty.

I do not see any wire going 'into the battery' positive cable/post.
I only see the positive cable going 'out of the battery' to the starter.

thanks

[hplacecf]

Originally Posted by Highsider

Is it premature to blame it on a faulty starter, after all of the above has been done?
Last summer I had "heat related" starting issues and a new $36.00 O'Reilly's cured it.

thanks, but I don't think it is the starter, since if I jump start the truck, or charge the battery, it starts right up.

seems like the battery is being drained and not recharged.

[OrrieG]

here is the wiring diagram, the generator charges thru the voltage regulator, to the ammeter, to the starter, to the battery. If it runs after getting jumped then the generator is making juice to run the truck. My guess is wiring associated with the charging circuit, possibly the voltage regulator itself. NAPA sell standard brand for less than $20. If the truck has been sitting and PO fubared the wiring there is a good chance he shorted the VR too. Just check one wire at a time for continuity thru the circuit, might be as simple as something not connected at the starter, ammeter or VR.

[hplacecf]

Originally Posted by OrrieG

here is the wiring diagram, the generator charges thru the voltage regulator, to the ammeter, to the starter, to the battery. If it runs after getting jumped then the generator is making juice to run the truck. My guess is wiring associated with the charging circuit, possibly the voltage regulator itself. NAPA sell standard brand for less than $20. If the truck has been sitting and PO fubared the wiring there is a good chance he shorted the VR too. Just check one wire at a time for continuity thru the circuit, might be as simple as something not connected at the starter, ammeter or VR.

good information; thanks.

some questions:

(1) when I turn the key to start the truck now (but it does not start due to the battery being drained), and/or when it was running, the ammeter needle moved. does that mean I have a good charging circuit from the generator up to that point?

(2) how would I go about performing a continuity test (I do not know much about electric). I have a multi-meter that I use to check the battery with - can I use that?, and if yes, how? Should the truck be running?

thanks

[hplacecf]

update:

I installed a new voltage regulator and made sure to polarize the generator.

still no good; same exact symptoms; not charging. so, I think my issue must be beyond the vr.


the wiring is hard to follow, and it looks like some rewiring was done to change out the distributor to an HEI model.

the ammeter needle appears to move once the truck is started. Would that mean the charging circuit is good up to the ammeter?

would it make sense, as an experiment, to run a wire directly from the battery terminal of the vr to the starter - thereby bypassing everything in between - to see if the battery will charge?

thanks

[hplacecf]

well, I bought some wire today. I will try a wire from the VR direct to the starter tomorrow (bypassing everything else).

at this point, I want to document what was wrong in case some other poor guy has the same issue in the future....

so far I did this:

new battery

new battery cable - positive - to starter (and wire brushed where cable attaches)

new battery cable - negative - to frame (and removed any paint or build up using a power tool until I saw bright metal)

new ground cable from the same point on the frame as negative battery cable up to the firewall (and removed any paint or build up using a power tool until I saw bright metal)

new ground cable from same point on the frame as negative battery cable over to the engine (loosened a bolt on what I think is the timing chain cover) and attached it there using the bolt (and wire brushed the area, though it was clean metal).

new Voltage regulator

after this, battery still does not charge when running, and drains slowly.

but, on the plus side, it loses it charge a bit slower than before, so I must be on the right track.

[Wheelie]

you need to get a volt meter and see what the generator is making directly at the generator. and work your way back to the regulator and closely inspect the engine harness.

[mr48chev]

One thing that everyone forgot to tell you is that "generators" do not charge very well at an idle as alternators do. They need to turn faster to produce a charge. A couple of the reasons they changed to alternators in the 60's were that generators couldn't keep up with the demand of extra equipment and your lights always go dim when you slow down with a generator as apposed to an alternator.

Does the ammeter needle move towars the + or the - when you have the engine running? It should be on the + side if it is indeed charging but it may not be charging enough to put a charge back in the battery along with running the ignition.

I'm going to assume that since you bought the rather spendy regulator and are fighting the generator that you intend to keep the truck pretty well stock with the stock stuff on the engine. That would mean you don't have plans to change to an alternator. With that I would suggest pulling the generator off and taking it to a starter/generator/alternator shop and having it tested or taking it to a parts house that has a tester it can be tested on. That is to make sure it works before you beat your head on the wall trying every other solution before knowing that it really works right.

On the ground to the engine, I'd suggest moving that ground strap to a bolt on the head or the block rather than the valve cover bolt. There should be an empty bolt hole on that side of one or the other that you can screw a short 5/16 or 3/8 bolt into to connect the ground strap solidly to the engine. Again you need bare metal under the ground strap to get a good ground.

[starterman99]

Connect your volt meter to the A or armature terminal on the generator,bring motor up to 1200-1500 rpm and see what voltage you get.Should be higher than battery voltage if not disconnect F terminal take a jumper wire and ground F terminal on generator to full field.This will bypass voltage regulator feild control and should make the generator charge wide open and you should see voltage well above battery voltage.that will tell you if the generator is working or not.do not leave F terminal grounded any longer than it takes to get your reading as it can damage the armature if you let it run too long.you should start with a battery that is fully charged up so you dont get misleading numbers.

[whitedog76]

This is why they went to using alternators.

[OrrieG]

Since no one had mentioned it, you said your battery is "draining". If you mean when it is running that makes sense. If when left overnight then you need to start checking for a short or something that is pulling power. Old school check is to disconnect and reconnected neg cable looking for a spark. Or get out the multimeter and check for an draw with the ohm meter. Power parasites are usually radios or steros that draw a little current to keep the memory alive, alarm systems, etc. Separate problem from charging the battery.

[hplacecf]

update.

I tried the ammeter bypass and nothing changed, but I found something that, no matter what, looks like an issue.


I took the generator off the truck and opened it up. on each side of the inside of the generator 'shell' there is a small metal clip screwed to the shell, and it is attached to a wire that is attached to some kind of small block (held in place by a spring - is that a brush?) that rubs against the inside part of the generator (the large core that can be removed).

each wire is composed of several twisted bare strands. but, on the one side, there was only one of the several strands connecting the block (brush?) to the clip. my guess is that this is not a good thing.

perhaps enough juice was being generated and passed that it could slow the drain of the battery as it was running (after the battery was fully charged), and keep the truck running for a while, but not enough to charge the battery.

I guess the next step is rebuild the generator to at least replace this wire, brush, clip part. what do you think? if yes, where do you get something like that done, or the parts to do it yourself?


now the 'core' has a copper section at the end. the copper looks somewhat clean and somewhat smooth.

above that is a large number of metallic strips that looks like it has paint of something on it that has worn off. does that sound right? or should that be bright metal?


thanks

[hplacecf]

Originally Posted by OrrieG

Since no one had mentioned it, you said your battery is "draining". If you mean when it is running that makes sense. If when left overnight then you need to start checking for a short or something that is pulling power. Old school check is to disconnect and reconnected neg cable looking for a spark. Or get out the multimeter and check for an draw with the ohm meter. Power parasites are usually radios or steros that draw a little current to keep the memory alive, alarm systems, etc. Separate problem from charging the battery.

it is draining while running. so I guess it is not something pulling power.

[hplacecf]

even though I still have an issue, or issues, I wanted to say thanks to everyone for the advice.

as a result of all of the different ideas and perspectives, I 'think' I am closing in on the issue and will have the truck running soon.

[hplacecf]

update:

took it to a local auto repair ship I use who works with a parts rebuilder.

i am having the generator rebuilt and will report back (again, for future reference).

[OrrieG]

Sound like it was ready for rebuild. All the parts you mentioned are replaceable, good idea to put in new bushing/bearing when you have it apart, when they get worn the commutator (spinning part) can get close enough to the case assembly to short. Happens on old starters too.

[hplacecf]

update:

some good; some bad....

picked up the rebuilt generator and installed it in the truck.

charged up the battery via a battery charger.

started the truck and immediately the ammeter indicator in the truck showed that it was charging (never did that before; previously it stayed around the middle).

hooked up a multi-meter and saw that the battery was charging and increasing up to about 15.+ (before it would start at around 13.+ and slowly drain down)

I smiled and thought hooray!

well, the truck does not have plates on it so I drove it around my property, and then let it run at idle a while - multi-meter still looking good at 15.+.

turned it off, went to start it, and it slow cranked on me and would not start... lol

multi-meter shows 12.7 or so before I try to start it, then it slow cranks for just a little and stops. i turn it off and the battery starts to climb back up to around 12.7 or so.

battery cable to starter is new,
battery is new,
I had wire brushed the starter post to be sure it was clean and tight,
but the starter looks very old (like the generator did before I had it rebuilt).

what do you think?

could it be the starter?

thanks in advance

[Wheelie]

Slow crank usually is a bad ground or low voltage to the starter. Those old starters draw a lot of amps when cranking so the wiring and starter need to be in good shape. Id check and see how many volts are right at the starter in comparison to at the battery, since you replaced the positive wire then its probably good but I noticed you didn't mention the ground. Its probably a ground or an internal starter issue.