Saturday, 31 May 2008

Ducati alternator windings or should i say starting problem

It started a while ago. I would return from work, switch the bike off to open the gate. Try to start the bike and it would not turn over. The battery was flat, quick check and it was only 11 volts. Checked charging voltage on the battery terminals and only 12.2 volts. Less with the lights on.

Started to investigate the connections from the alternator and they are discoloured. Not a good sign. Although if its the issue then success. Tried cleaning all the connections reconnecting, checked voltage still no good.

Posts up on the Ducati site for help, Lots of advice, battery possibly, voltage regulator and alternator, stator etc.

With the help of a forum user, checked the output from the alternator by disconnecting the two yellow wires, placing a meter on the end and checking the output. Also to check the ohms resistance between each wire and to earth. The ohms values seem to be in range. 0.03 between each wire and no leakage to earth.......but the output is OK so that must mean the regulator rectifier is faulty.

Mike was brilliant, i had ordered a voltage regulator, forgot that the block connector is burnt and the connectors discoloured. Mentioned this and a new one arrived the next day in the post. If only all companies acted this way.

A few days later, the new voltage regulator back on. picture shows new connectors also with Mikes advice i solder the connectors. Took time to crimp the new connector. Checked the output and still not over 12.4 volts charging. I have made a mistake.

Now i phone Pat at Viking motorcycles. He tells me to check the output values with the workshop manual.

Check the values and i find....
The readings from the alternator should be only 0.2 to 0.4 ohms. Previous readings differ.
The output from the alternator should be
35 volts at 1500 revs
70 volts at 3000 revs
140 volts at 7000 revs

From memory i could only achieve around 20 volts on tick over and a maximum of 40 volts.......Now i wished i had taken time to read the manual and to discus the issue with Pat first. It could have saved me spending some money and trying to pinpoint the outcome.

moral of the story
take time to research the correct values and how to check. Save yourself some money.

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