charging problems...

[Lang]

Lynne,

The thing that is really strange is why does the generator polarity change?

I can understand your solution if the generator is not doing its job as you say but swapping from + to - is weird. Maybe Svenn is just assuming this is happening and flashing an already correctly polarised generator while chasing the problem you suggest.

Lang

[motto (RIP)]

I don't think it's reversing polarity Lang. It appears that the residual magnetism is insufficient to enable a high enough voltage to be developed to pull in the reverse current relay.
The first thing to do, I would think, is to monitor voltage output which should be between 7.2 and 7.4 when charging.
I would like to know the fix for this one as my Dodge has started doing the same thing.
Someone out there has the answer.

David

[Lang]

David,

What about starting at the generator to take each element standing alone. The raw output from the generator should be well over 20 volts. If that is OK it should eliminate the generator and direct attention to the voltage regulator?

Lang

[Lynn Eades]

Svenn, if you drop the belt off, and then supply power to the big terminal, the genny should run as an electric motor. If it will do this, I would clean the contacts in the regulator.
"Motoring" the generator, is a quick way to check it's overall condition. If it won't "motor", then it needs work. If it does, then it's likely the regulator.
A quick way to check if anything is happening is to turn on the headlights. if you then start the engine, with a few revs on, the lights are generally are brighter, because the voltage has risen above battery voltage.

[motto (RIP)]

Lang

I did a simple check on the generator and it came up ok.This consisted of dropping off the fan belt and pushing the reverse current relay points closed. This is the double set of points in the regulator. Do this and the generator should motor over in the normal direction of rotation. All is good so there must be a glitch (technical term) in the regulator. What this may be I don't know. Faulty resistor perhaps?

Dave

[Lang]

Dave,

Are you 6v or 12v?

If you are 12v there are some fantastic solid state regulators that work with both generator or alternator. About the size of a matchbox so will fit inside the old regulator cover. I don't know enough about them but maybe also available for 6v?

Lang

[motto (RIP)]

The truck is still on 6 Volts Lang.

Dammit, the thing's been good for 70 years. If I can get it sorted it should see me out.

David

[Lang]

How far do you drive these days? Just carry a spare battery to see you through the day!
Lang