02-12-2023, 03:34 PM
Bumping up and updating the progress on this thread;
My rebuilt working dynamator has expired. I’ve never tried to get it to charge a flat battery but only normal starting and running loads. Charging flickered and then stopped after a few hundred miles. Drat! Taking it apart, again, I found that one of the brushes fell out of the brush box, the braided tail having parted. Yippee thinks I - that's it! The rotor still tested out at 4 ohms with continuity through the new replacement generic brushbox and the rectifier pack tested OK with the diode facility on my multimeter. There are no obvious indications of battery drain back when turned off.
After rebuilding and getting everything back together, still no charge and the red light solidly on. It must be the (original) regulator thinks I. So I obtained the suggested generic replacement, cut out the regulator and wired that in. It was obvious which was the earth but not which way round the other two leads should be. Tried it, still no charge. All apart again and reversed the regulator connections, back in, still no charge. I may have inadvertently blown the regulator so I’ve tried a different one, wired out of the body to make wire reversals and regulator changes easier even though it looks a bit naff. Still no charge, even when the wiring was reversed.
I don't know where to go next? The rotor circuit seems OK, the diode pack tests out OK and I've tried two new regulators. Would having the regulator wired the wrong way round blow it? Is there a way of testing them?
Asking the audience for your collective experience of testing alternators in more modern machinery - is there anything else I could do or test? And as before, I’m wedded to 12 volts and have had similar difficulties with dynamos, maybe I’m the common factor in all this?
Thanks in anticipation, Dave (aka Speedex750; previously)
My rebuilt working dynamator has expired. I’ve never tried to get it to charge a flat battery but only normal starting and running loads. Charging flickered and then stopped after a few hundred miles. Drat! Taking it apart, again, I found that one of the brushes fell out of the brush box, the braided tail having parted. Yippee thinks I - that's it! The rotor still tested out at 4 ohms with continuity through the new replacement generic brushbox and the rectifier pack tested OK with the diode facility on my multimeter. There are no obvious indications of battery drain back when turned off.
After rebuilding and getting everything back together, still no charge and the red light solidly on. It must be the (original) regulator thinks I. So I obtained the suggested generic replacement, cut out the regulator and wired that in. It was obvious which was the earth but not which way round the other two leads should be. Tried it, still no charge. All apart again and reversed the regulator connections, back in, still no charge. I may have inadvertently blown the regulator so I’ve tried a different one, wired out of the body to make wire reversals and regulator changes easier even though it looks a bit naff. Still no charge, even when the wiring was reversed.
I don't know where to go next? The rotor circuit seems OK, the diode pack tests out OK and I've tried two new regulators. Would having the regulator wired the wrong way round blow it? Is there a way of testing them?
Asking the audience for your collective experience of testing alternators in more modern machinery - is there anything else I could do or test? And as before, I’m wedded to 12 volts and have had similar difficulties with dynamos, maybe I’m the common factor in all this?
Thanks in anticipation, Dave (aka Speedex750; previously)