1963 Dodge 880 - Charging problem

[oedipussy]

I'm stumped on this one. I've got a '63 Dodge 880 with a new alternator (replaced less than one year ago), regulator (2 weeks ago), and resistor (a few months ago), the car is generating its own power (runs after disconnecting the battery) but it ISN'T charging the battery. Changed the battery a month or two ago, same problem. Changed a few wires that were burned up but there are still some that look mildly questionable (just a crack or two in the plastic), I don't really think that's contributing to this problem though. Nothing looks obviously wrong with it., and it was charging the battery up until a few months ago. Any ideas? Thanks.

[vgames33]

Are you sure something isn't sucking your battery dry? Maybe something is staying on when it shouldn't (trunk light, for instance).

[oedipussy]

There's nothing I can really think of that would be doing that. The car doesn't have AC, no power steering, brakes, windows, locks, etc., pretty much everything is manual. It doesn't even have a clock. About the only things I use regularly are the radio and when needed the headlights. When I drive it during the day it seems to be a very small drain, but using the headlights totally kills it, which is understandable as the battery isn't getting any juice back to it. I've driven it a few times during the day without even using the radio and still the battery does eventually die.

[oedipussy]

I suppose I should add that when the car is parked and everything is turned off the battery isn't draining. It only happens when it's running.

[UncleBob]

gonna hafta use a multimeter and get some data. Only way you'll diagnose it accurately

[oedipussy]

Yeah, I was planning on doing that when I have the time, I was just hoping someone could help narrow it down a little. The whole problem just doesn't make any sense to me because the car is putting out power - the battery SHOULD be charging.

[UncleBob]

all you know is the alternator is putting out *something* but not enough. Thats far from enough info to narrow down where the problem lies

[oedipussy]

I guess that's true, thanks. I suppose I just really have to go through the entire electrical system (not exactly my area of expertise).

[bobss396]

You could still have a bum battery that won't accept a charge. if it has a history of abuse it could have a plate short inside it that you can't see.

I would still go for a full charging system and starting system check. Most Sears or Pep Boys do them reasonably.

Bob

[Selectron]

Have you hooked a multimeter onto the battery to check if the terminal voltage rises when the engine is running? If your battery is healthy and in a reasonable state of charge then it should read around 12.6V after being parked overnight but before starting the engine. Upon starting the engine that should rise, thereby demonstrating that at least some charge current is reaching the battery. At 1963 vintage it would, I think, have been too early to have a semiconductor-based voltage regulator - I think some kind of mechanical, coil-based regulator would have been in use at that time but I don't know what the typical voltage readings would have been for those. Nonetheless, I'll just list the typical voltage readings which you would expect to see from a modern charging system:

Voltage after sitting overnight, but before starting engine - should be around 12.6V (indicates that there is no excessive current drain with the ignition in the Off position, and that the battery is capable of holding a reasonable level of charge).

Voltage with engine idling - should be thirteen-point-something volts - typically around 13.6V or maybe as high as 14V (indicates that the alternator is producing output current, and that that current is reaching the battery. Also indicates that the rectifier is functioning, converting AC to DC).

Voltage when revving engine slightly - should climb to around 14.2V and then hold steady at that voltage regardless of further increase in engine speed. (Indicates that the voltage regulator is functioning, and clamping the upper voltage threshold at the correct level).

The first of those readings will apply to your vehicle but the second and third may not - they could easily be somewhat lower depending on what type of voltage regulator is fitted. Do you know if the regulator has been upgraded to a modern equivalent, or would it still be of the same type that was fitted as original equipment?

If you have a wiring diagram for the charging section - that's the alternator, rectifier, voltage regulator and battery then I'm sure there are a few of us here who could suggest some tests if you were able to scan it and upload a picture.

I don't think your battery has developed a high internal resistance (sometimes referred to as internal impedance) because if it had then it would be struggling to operate the starter motor, and by the same logic, I wouldn't suspect a weak cell either (I assume it cranks and starts readily so long as the battery is fully-charged?) It sounds like an open-circuit somewhere between the alternator and battery, causing the battery to receive no charge current. If you have a diagram you could upload that would help a lot.

[oedipussy]

Thanks for the help. I'll try to do the multimeter test tomorrow and I'll let you know what happens with that. I do have all of the wiring diagrams for the car but I probably wouldn't be able to scan them, sorry.

Everything on the car is original equipment. I was pretty sure that the regulator was coil-based but opened one up to check any way. I'm not exactly sure what a semi-conductor would look like, but I didn't see anything that wasn't mechanical. There weren't any computer chips in it or anything.

As far as it being a bad battery, I already ruled that out as I replaced the first one with a brand new one and still had the same problem. Not to say that it would be impossible - but rather unlikely. And yes, the car cranks and starts easily as long as there's enough juice in the battery.

[vgames33]

I've had to return three batteries in a row before. Don't rule it out just yet.