Haflinger Charging Light

[101RRS]

The charging system in my Haflinger is a generator system with an external voltage regulator.

In my vehicle I have replaced the old (Series 1 LR style) voltage regulator with a Bosch electronic model. Normally when the engine is below 1200RPM the ignition light is on and above that it is off (all normal for these vehicles). Normally my voltage meter shows 13.8v when driving around.

Recently I have noticed the voltage has been down as low as 11.5v when driving around with the lights on when normally with full electrical load it would be above 13v.

When testing the battery at rest it was always between 12 and 12.5v and even with the engine running it was the same indicating it was not getting enough charge. At the generator it was pushing out 14.8v (normal) but only about 12.5v at the battery indicating either a dry joint between the regulator and the battery or a dud regulator.

So I replaced the voltage regulator and all fixed - now back to 13.8v light load in the system so a faulty voltage regulator.

So my question is - how come the charging light all worked as normal when clearly the system was not generating enough power to recharge the battery. Below the usual 1200 rpm the charging light was on, and over 1200rpm the light was off even though the battery was not being charged.

Thanks

Garry

[bee utey]

It depends on how the charge light is rigged, the indicator may be switched off by current flowing from the armature. The current may be insufficient to charge the battery under load but enough to turn off the light. It's been a while since I last worked on a genny.

[101 Ron]

Usually on a generater system the charging light is switched by the cut out contacts in the reguator............
As mentioned..........the system was charging, and the light was showing that.
Just it was not enough.

[101RRS]

Thanks for the comments - so in reality the charging light is only effective if the actual generator has failed rather than components further down the charging system which results in a lack of charge to the battery.

I guess the same applies to the charging system in a series 1 Landrover.

garry

[PhilipA]

For an electronic regulator, the charging light registers the difference in voltage between the alternator and battery.

So when the ign is On , but engine not running the alternator is producing zero , but the battery is 12v , so the light is bright.
If the light shines in a dull fashion after the engine is started , it means there is a voltage difference between the alternator and battery.
This can be poor connections on the positive, inadequate gauge wiring, or poor earths.

As a test you could use a jumper lead for starting to connect the alternator/regulator positive to the battery positive to see if the light changes , and do the same from the alternator body to the negative.
Regards Philip A

[jillr]

Another possibility, the electronics may have only half failed. I've seen bridge rectifiers for instance with only half the bridge working. So the electronics supplying the lamp may have been OK but the parts (e.g. transistor or SCR) supplying the battery may have been so low in gain as to be ineffective.

[101RRS]

The charging system in my Haflinger is a generator system with an external voltage regulator.

In my vehicle I have replaced the old (Series 1 LR style) voltage regulator with a Bosch electronic model. Normally when the engine is below 1200RPM the ignition light is on and above that it is off (all normal for these vehicles). Normally my voltage meter shows 13.8v when driving around.

Recently I have noticed the voltage has been down as low as 11.5v when driving around with the lights on when normally with full electrical load it would be above 13v.

So I replaced the voltage regulator and all fixed - now back to 13.8v light load in the system so a faulty voltage regulator.



So I replaced the Bosch electronic voltage regulator back on 14 Nov 18 and have only covered about 500km since. Drove tonight and voltage was up around 13.5v with the headlights on. Driving back home voltage is back down to 11.5v so it looks like the voltage regulator has failed again.

Putting aside the obvious issue that I just got a dodgy voltage regulator, it there anything in a basic generator system (like is in a Series 1 LR) that can kill regulators?

Thanks

Garry

[Milton477]

Had spotties on mine so the dynastart copped a flogging when on high beam.

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