I'm running a quite non-standard '59 A10 and it's stopped charging the battery. What's happened so far;
Was working fine but while I was sorting out a problem with rear light I found that the battery wasn't charging from the dynamo. It charges fine from a charger.
Checked the out put of E3L dynamo and it was showing about 1.6v.
Checked resistances, F---3 ohm, D---0.6 ohm. OK.
As the bike hadn't really been used for a few months I decided to "flash" the dynamo.
After the "flash" I tested the output again and now it's showing a NEGATIVE output of about -1.6v.
The dynamo was professionally rebuilt some years ago by Dave Lindsley but has only done about 2k miles in the last 7 years.
It's set up through a 6 - 12v conversion regulator, negative earth and driven by a "Hawker" geared up belt drive.
Help!!! How do I fix it???? Please give any answers in the simplest of terms!
When you are checking the dynamo output, you are joining the D and F wire together, with one meter lead on the two wires and one to the earth. A 6 volt dynamo will easily put out 18 volts like that.
Hi idie, Yes doing exactly that. I've been following the info given on "MatchlessClueless" site.
Belts not slipping. I know they are notched but dynamo could have moved or the pulleys aren't tight enough. Usually dynamos are very reliable but can overheat and throw the solder off the commutator.
Quote from: idie on 06 May, 2023, 17:48
Belts not slipping. I know they are notched but dynamo could have moved or the pulleys aren't tight enough. Usually dynamos are very reliable but can overheat and throw the solder off the commutator.
I'm going to check belt today but that wouldn't account for NEGATIVE output no matter how small........would it????
If the battery is wired as neg earth then flashing the field wire to the positive live will polarize the dynamo the correct way round.
Hello Rick
Most voltage regulators require dynamo field coil flashing as you are doing, however some voltage regulators require a non standard dynamo internal wiring and the method for flashing the field winding is different. The Podtronics voltage regulator is an example. Consult the installation instructions for the regulator if you have them or let us know the make of the regulator and maybe someone can provide further help.
If flashing doesn't help, the next step is to check the brushes and clean the comutator with a cloth soaked in fuel. See BSA Service Sheet 809.
Jim
Thanks for all the advice. I'm now at my wits end with this.
I'm trying to contact Dave Lindsley, the mag and dynamo magician. The number on google no longer connects and the page says his workshop is permanently closed. I know he's still working because one of my contacts was speaking to him a couple of weeks ago.
Can anyone put me in contact with another dynamo magician preferably in the Somerset / Dorset area.
Thanks again for your info. Rick.
You have the best dynamo/mag man around just on your dorstep. APL in Shaftesbury.
Thanks for info. Just been speaking to A.P.L. Magnetos. Visit has been arranged.
Cheers, Rick.