Packard Forum Index » General

There are quite a number of 6 volt cars around me, and being a contrarian I love to go and start them up in cold weather and when they have been sitting for a long time. 'cause they do. But I do know the difficulties that people have and I know the troubles my customers bring me. As noted in another thread, clean connections and good cables are a big help.

But here is what I noticed lately and now I am on a search and destroy mission. My low mileage 50 Commander (Delco system, just like a 50 Packard) has always started quite OK, and shows a good charge on the ammeter, keeps its battery up, etc. But the headlights were wretched and the dash lights though not sunburnt were dim. They are the glowing type, like 22-23d series. For grins I tossed a voltmeter across the battery while it was just sitting and saw only 5.7v. A standing 6v battery should read about 6.3 just as a standing 12v battery should read 12.5 or so. So I cranked the old girl up and discovered that she was only putting 6.4 volts across the battery at the best. Charging voltage is supposed to be 7.2-7.4 volts. (14.4v on a 12 volt car)

Inside the regulator of most any of those generator equipped cars are three relays. One disconnects the battery from the generator when you turn the car off, one limits the total output so the generator does not commit suicide, and the third regulates the amount of current to the field which in turn determines what voltage the genny makes. That one is a magnetic coil in a sort of tug of war with a spring loaded contact. Contact closes, voltage goes up. Voltage too high the coil tugs it open. All that to say one adjusts the spring tension to adjust the voltage. Older Delcos elegantly have a little screw to do this. Others you have to bend the spring hanger.

So with everything well and truly warmed up I put the 50 on a good high idle, turned the parking lights on and then set my voltage to 7.5. The voltage drops about.2v when you put the cover on the regulator because of some magnetic effect, so I ended up with 7.3 all done. It took a long drive to bring the battery up to its new correct baseline. But now the car leaps to life when I punch the starter and the 73 year old sealed beams are as they should be--as is all the lighting.

Checking through inventory I am finding voltages all over the place, but none too high. My 41 was only .4 v low, but adjusting made a nice difference. I suppose that over the years the regulators are losing spring tension and the contacts do erode from constant action. So with a quarter turn of a small phillips screwdriver you can bring the car back to standard condition with very pleasing results. Try it, you'll like it.


Just to underline: go for a drive and get everything warmed up. Set the idle up nice and high, put the parking lights on to make a little load. Set it to 7.4 and let it run for a few minutes to stabilize. When you put the cover back on the regulator it will drop to 7.2. The ammeter will of show a moderate charge at first, but after the battery has come all the way up the needle will go back to the middle. My 50 was charging at about 10 amps at first as it had a lot to make up. If the ammeter continues to show a heavy charge something is wrong and you need to go back and recheck.

Chronic low voltage makes for a tired battery, a lazy starter, and yellowish lights. Ignition system performance, eespecially when cranking the engine, will be reduced.

Voltage regulators are delicate things, and care and a good meter are needed when attempting to adjust one. Overcharging/overvoltage is bad, too, and will lead to burned out bulbs and battery issues. I'd want to start any adjustment procedure with a good battery that is fully charged, or very close to it. A low battery or a battery in poor condition may make adjustment more difficult. As always, all connections should be clean and tight. A regulator that has had moisture inside it will usually show some internal corrosion, and may not accept or hold a proper adjustment, and one with badly burned points may not be reliable. Ideally, the inside of the regulator will look shiney and new, and the points will have minimal erosion or burning.

This is a very timely topic, as I'm just had my generator rebuilt after it got hot and upon inspection I found it had "thrown solder" Shop calibrated my regulator at the same time, which was okay for a bit, but then started acting up, not charging. Generator was fine, it was regulator troubles. Had two spare regulators, one didn't work, the other did.

My car, 53 Cavalier, should have a 45 amp regulator, but the one on it is 41 amp, is this potentially a problem? The one that was on when the generator died was a 41 amp as well. The "Voltage Regulator" points were burnt, which I don't know if that was what caused my generator to burn up, or happened because my generator burned up? I'm thinking I should get a new regulator, the proper size.

Did I see somewhere on here that someone was making a solid state regulator that looked like the factory regulator? Or did I see that somewhere else?

Happy Sunday!

Thanks for the tips Ross! I'm going to give this a go tomorrow and see what happens.

-Kevin

Check this stuff out!!! I didn't know any of it past the charging voltages. I'll wager that the '46 could use a screw turn herself. It does hold the battery up. It's a good battery and will stay up all by itself for many weeks at a time.


More innerestin' than the NFL draft . . . .


:rolleyes:

In the case of replacing a specified 45 amp regulator with a 41 map regulator, I don't think you'd have any trouble at all. You'd just have a slightly lower maximum charging rate, which the generator will appreciate.

Sometimes, tapping lightly on a balky regulator with a screwdriver handle will get it working again. It may keep working for a long time, or it may not. Always check all connections, including any ground wires between the regulator and the generator. If the car has an engine to frame ground, it should be in good condition. If it does not have one, adding a substantial ground cable between the engine and the car frame may improve the starter performance and generator reliability.

Quote:

I’m working on a solid state regulator which so far is in the prototype stage and in the Delco-Remy style. However, while switchable from 6v to 12v, the design is only negative ground as I’ve not yet found one for positive.

As long as the 41 amp has current regulation it will be fine, as it will regulate the generator current to its capacity. If not, it could be a bit of a problem, but that's still only a 10% difference if mated to a 45A generator.

The high current output would only happen at a lot of accessories on and/or a very discharged battery.

Quote:

If one day you do one for a 6v positive ground let us know! I'm not a big fan of too much "modernization", but for something that makes the car more reliable and is easily changed back, that's okay.

Quote:

Lights, heater fan, horns and Pwr Ant........I think I should be okay with 41 amps! Thank you!