Author Topic: 1972 cb500 - Charging system issue  (Read 19991 times)

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Offline Anghil

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  • My first bike! '71 CB500
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Re: 1972 cb500 - Charging system issue
« Reply #75 on: October 28, 2013, 03:40:46 PM »
Cool thread!I hope to see updates. I'll be checking this for issues with my bike. Currently not charging the battery, and it's new!
Always looking to learn something new.

Offline 750 Cafe Commuter

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Re: New Project 1972 cb500 - Charging system issue
« Reply #76 on: November 02, 2013, 09:49:14 AM »
one step forward and two steps back.
I replaced the alternator, with a used one, and the system is not charging still.
I performed the test again and found that the RR is faulty!
i did the following:
Stop the engine. Switch the multimeter to DC-Voltage (DCV or Vdc). With the block-connector disconnected
as above, connect the multimeter-leads up to the two extra wires in this connector (apart from the three
YELLOW wires), this in the connector-block emerging from the wiring-loom, not the other side going to the
generator. If there's only one extra wire, connect it to one multimeter-lead and connect the other multimeterlead to the engine-casing. When you switch on the ignition, Check the reading on the display.

I got about 0.4V instead of 12V = RR at fault. Replace it with a new one.

that sucks because it was a new unit.
is there a way to repair it, what could have fried it?

Cool build!  I'm working on a CB750 K8 and having the same charging issues.  Have replaced the RR, stator, field coil, wire harness, and battery.  All the components test out ok, but still not charging!  Hard to enjoy riding when your engine could sputter to a stop any moment.  I finally took it in to a shop here in Seattle that's supposed to be good with 70's Hondas.  When I find out what the problem was, I'll definitely let you know.  I'm assuming it's a bad connection or short somewhere.  Not sure what else it could be.  Keep up the good work!

Offline zenocchio

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Re: 1972 cb500 - Charging system issue
« Reply #77 on: November 02, 2013, 07:04:45 PM »
Thanks mate for sharing! I am going to tackle this in the next couple of weekends, I really hope to get to the bottom of it.