Electrical: Does this sound like a voltage regulator issue?

[StudeMann]

A week ago I drove my stock 51 LC about 20 minutes at highway speed to a family dinner. I noticed a couple of times that the ammeter needle seemed to be jumping around. On the way home I had the headlights, the climatizer/defroster fan and the radio all going. My dash lights don't work so I couldn't see in the dark what the ammeter was doing. When I got home and turned the engine off to get out and open the garage door, the starter would only give a small groan but wouldn't turn the engine over. The 4 year old battery was nearly dead.

The next day, I charged the battery and the engine started easily. However, the ammeter was showing nothing whatsoever (no charge OR discharge) even when I turned off the engine and turned on the headlights. Since the ammeter is showing nothing this seems to me to indicate a problem with my voltage regulator rather than the generator. Am I correct?

If it is a problem with the voltage regulator, should I attempt to repair/adjust it or replace it? Neither the VR or the generator are the OEM Delco Remy products so my Studebaker shop manual won't help too much.

Thoughts and suggestions are welcome.

Thanks,

Jim

[Corvanti]

possibly that or the generator, but first i'd check the cables/wiring for corrosion, looseness or a frayed condition - especially if you are still running a 6 volt system (as i am).

i had a similar problem a few weeks ago. it turned out to be a bad "green" on/off switch connected to the battery, but i did find the cable from the battery to the solenoid a little loose. i took the switch off, cleaned all the connections, tightened and was good to go.

[altair]

charging system

A week ago I drove my stock 51 LC about 20 minutes at highway speed to a family dinner. I noticed a couple of times that the ammeter needle seemed to be jumping around. On the way home I had the headlights, the climatizer/defroster fan and the radio all going. My dash lights don't work so I couldn't see in the dark what the ammeter was doing. When I got home and turned the engine off to get out and open the garage door, the starter would only give a small groan but wouldn't turn the engine over. The 4 year old battery was nearly dead.

The next day, I charged the battery and the engine started easily. However, the ammeter was showing nothing whatsoever (no charge OR discharge) even when I turned off the engine and turned on the headlights. Since the ammeter is showing nothing this seems to me to indicate a problem with my voltage regulator rather than the generator. Am I correct?

If it is a problem with the voltage regulator, should I attempt to repair/adjust it or replace it? Neither the VR or the generator are the OEM Delco Remy products so my Studebaker shop manual won't help too much.

Thoughts and suggestions are welcome.

Thanks,

Jim

Disconnect the leads to the generator and connect a multimeter, at 1000 - 1500 RPM the meter should read 40 volts.(Also confirm the generator housing is appropriately grounded) If the foregiong fails, snap the cover off the gen and inspect the commutator for excessive oil accumulation and/or worn brushes. If the commutator is contaminated get a narrow paint brush to fit through the space, with a little gas on the brush, run the brush against the contaminated commutator while the engine is idling, if contaminated it should come to life. If there is no action from the generator it may have to be removed, good luck Dave

[StudeMann]

Disconnect the leads to the generator and connect a multimeter, at 1000 - 1500 RPM the meter should read 40 volts.(Also confirm the generator housing is appropriately grounded) If the foregiong fails, snap the cover off the gen and inspect the commutator for excessive oil accumulation and/or worn brushes. If the commutator is contaminated get a narrow paint brush to fit through the space, with a little gas on the brush, run the brush against the contaminated commutator while the engine is idling, if contaminated it should come to life. If there is no action from the generator it may have to be removed, good luck Dave

40 volts seems quite high. Are you aware mine is a 6 volt system?

[RadioRoy]

There are two simple tests that are easy and non-invasive.

With the engine running at a fast idle, ground the field terminal on the generator. That's one with the skinny wire. Look at the ammeter while you goose the engine.

Remove that jumper and connect the ARM to the BAT terminal on the voltage regulator. Look at the ammeter while you goose the engine.

Make sure you remove the jumper before shutting the engine off.

If the ammeter shows a charge at any time, the generator is good and the voltage regulator is bad. If no charge, the generator is bad, and the voltage regulator could still be bad as well.

All you need is a jumper wire with clips on the end. Not a battery cable jumper, but one of those little ones that electronics guys use. Make it from regular hook-up wire, at least 18 gauge or bigger. You can use lamp cord if you like. Put an alligator clip on each end.

[altair]

generator

40 volts seems quite high. Are you aware mine is a 6 volt system?

Yes the regulated system is 6 volts but the generator unregulated will put out 40 volts. If you look on the tag it will display the max voltage.

[Dan Timberlake]

In the 59-64 shop manual there is section on (12 volt) generator testing.
Page 7A begins the regulator testing section.
First they want me to be sure the a batery is fully charged, with a specific gravity over 1.250.
Next they want me to test the quality of the ground connection, using a volt meter to measure the volage drop
per attached image.

Previous section went over testing the generator performance measuring ouput amps after attaching a test lead from the gen Field terminal to either the regulator base (ground) or the gen armature terminal, depending on generator type. I do not have 6 volt test procedure close at hand.
A standard multimeter would handle the < 0.3 volt DC measurement for the voltage drop test.
A DC ammeter capable of reading full load amps is rare, but there is one in the dashboard I guess.

[altair]

generator

Disconnect the leads to the generator and connect a multimeter, at 1000 - 1500 RPM the meter should read 40 volts.(Also confirm the generator housing is appropriately grounded) If the foregiong fails, snap the cover off the gen and inspect the commutator for excessive oil accumulation and/or worn brushes. If the commutator is contaminated get a narrow paint brush to fit through the space, with a little gas on the brush, run the brush against the contaminated commutator while the engine is idling, if contaminated it should come to life. If there is no action from the generator it may have to be removed, good luck Dave

Please accept my error it should say 40 amps @ 6 volts

[rstrasser]

Studeman you state in your first post that the amp meter needle does not move off of center. When you turn on the ignition key without the engine running the needle should go to - and if you turn on your lights it should go more -. If it does not there is something amiss between the generators output terminal,the amp meter and the battery.
Not all generators ground the field terminal through the regulator. You need to find out how the generator that you have powers the field coils that are inside the generator. Some are powered from the regulator and others are powered internally inside the generator.
Once you connect the field correctly you should see the generator voltage output increase to a value of a volt or so above battery voltage and the amp meter should show a charge; as you rev the engine.
Need more information to be of any further help.

[altair]

Please accept my error it should say 40 amps @ 6 volts

I had a 6 volt generator bench tested about a month ago and it produced 40 amps and 20 volts

[StudeMann]

I'll check the integrity of the connections & wiring and the generator output this evening and report back what I find.

Jim