Red charging light on when ignition is off.

[matthew henricks]

I searched but did not find anything like this.

1960 Single cab. Stock but 12V. Wire harness is solid. (Wiring works about 100 miles ago.) 1600 SP if that matters.

Driving it last week i noticed when i went to start it up the red charging light was on before i had even put the key in. Turn the key and it goes out but green light goes on. Started and drove fine but it was not like this a few weeks back.

After sitting for a few days the battery now dead. Where do i start looking?

Ignition switch? Generator? Voltage Regulator?

Thanks for the help.

[busdaddy]

Try giving the voltage regulator a couple of whacks with the handle of a screwdriver, that may get the contacts unstuck, that will buy you some time to find another regulator.
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[telford dorr]

Better also check the generator - give it the sniff test, see if it smells burnt. If the regulator cutoff relay sticks, the battery will dump into the generator when the engine is off, and generally cook it.
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'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
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[matthew henricks]

Thank you guys. I will give things a once over this week.

[OB Bus]

[matthew henricks]

Did some tapping on the regulator tonight and the red light is now off. I also smelled the generator and smelled normal engine smell so maybe it is OK?

Regulator will come apart for a cleaning and we will see what we have.

Thank you for the help.

[matthew henricks]

Well, I was fooled.

The red light was on while the ignition was off because the wire from the red light to the regulator had fallen off and come to rest on the positive battery terminal that goes to the battery. Hence the bulb simply had power.

I took the regulator apart and cleaned the points. For sure some black in there but not bad. Put it all together and now i have the classic red light on while the engine runs.

I put my DMM between the red and green line on the generator and got readings all over the map from near zero to around 6V. Not sure that is the right way to check it so off to do some reading.

[BarryL]

Glad that's all it was.

To read the generator output put the meter's + on the generator D+ (large wire) and the - on the body of the generator (ground or earth).

Of course be extremely aware of the pulleys and belt as you are.

[matthew henricks]

Thanks Barry. Did that with the engine at idle and got readings all over the place. (DMM on DC with 20V range) I did this with the voltage regulator still electrically attached.

Going to check the brushes tonight to make sure they are still long enough to contact the armature. If they are then i will re-test the voltage again before concluding the generator is toast.

[BarryL]

[matthew henricks]

More trouble. Driving yesterday the red light came on for about 3 minutes and then went off again. Bus drove fine and started fine. No glowing of light. It was totally off then came totally on and then went off again.

- Voltage at generator + is 13.1V at moderate RPM using DMM.
- Voltage at battery engine off is ~12.4V. using DMM.
- Voltage at battery with engine at moderate RPM is 13.1V using DMM
- Regulator was taken apart and points cleaned.
- Generator brushes are below the top of the holders by about 1/8" but there is plenty there and good spring force.
- Generator commutator is relatively clean.
- Battery is about 3 years old but takes a charge fine with trickle charger.
- Battery terminals are clean.
- Wire harness is new. Well 20 years old but unmolested with maybe 100 hours on it.

Any ideas? I hate to just replace parts. Regulator is easy but i really loath a generator swap right now. Searching for clues in other threads...

[telford dorr]

If the brushes are below the tops of their holders, they're done - replace them before the arcing ruins the commutator.
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[BarryL]

What he said ^^^^. In an emergency while travelling I've whittled a piece of wood to go between the spring and brush till I could make the full brush swap.

[Abscate]

IF they have gone long with out service, pull the brushes out and clean the grooves of the armature carefully with a blunt, non-metallic object to get all the carbon out of there, too.
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[matthew henricks]

Brushes replaced yesterday. They were less than half the length of the new ones. Cleaned the armature the best i could but it was pretty clean already.

A short test drive and all seemed fine but i have been fooled too many time the last few month by this old bus...

[matthew henricks]

Thought i would wrap this thread up. Brushed did not solve the problem. After cleaning the contacts inside the regulator i got about 10 miles of trouble free and then the light was back on. It would go out when i would tap on the housing but it was a clear indication that the regulator was on its way out.

A new one was installed and so far so good.

Thank you for the help.

[matthew henricks]

Need some help again here guys.

New/NOS Bosch 12V Regulator was installed back in January. Bus has maybe 500 miles on it since and the red light is back on.

Tap the regulator housing and red light goes off for a few days and then back on. Done this three times the last week over maybe 20 miles.

Soo... How does one trash a regulator that looked new in 500 miles? Is there something else that should protect it?

Thank you.

[telford dorr]

Poor quality regulator. Being "new" these days is no longer a guarantee of quality (thank you, china...) Try another one. Try an electronic version (no moving parts to "stick" - but be careful - the case on these is connected to battery "+"...)
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)