Author Topic: CB500 Electrical Issues  (Read 434 times)

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Offline MCCB500

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CB500 Electrical Issues
« on: May 21, 2021, 02:23:56 PM »
Hi all,

*I have scanned through the web for similar issues. But nothing that can magically solve my problem yet.*

Been lurking on this forum for some time now, and today is the day I post :).
I am faced with an electrical issue. I have done some preliminary checks and wanted to see if you guys can push me in the right direction before combing through the electrical system.

Back story - The bike ran fine. Recently had its carbs cleaned, oil changed, valve gap'd, cam tension'd, new sparks, forks replaced, new petcock, and did nothing to the electrical sys.


// Here is what happened //
After completing the maintenance service, I put gas in, go turn on the ignition. All lights are on and everything seems normal like it used to be. Hit the starter button, and boom - lights off - and did hear the starter solenoid go "click" once (i think).


// Here are some quick and easy things I have looked through //
Battery - Tested at Napa - Passed - 12.8V
Battery Terminals - Looks good
    -->Supplying Voltage to the starter solenoid
    -->15A Fuse not Blown, swapped in a couple of new ones to test too
Winker Relay - Looks like it has continuity
Wiggle all connectors
Looked for shorts and bad grounds
Drink beer, wait, and still no power


// What's next? //
Maybe pull out starter solenoid to test - would it cause the whole sys to go down?
Test Silicon Rectifier & Regulator - but that should be used for AC/DC conversion no?
Ignition switch bad?
What component would cause the system to go down if not the ignition switch?


Thank you guys for hearing out my rambling.
I am a noob, and any help is greatly appreciated :). Thanks in advance!

Offline TwoTired

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Re: CB500 Electrical Issues
« Reply #1 on: May 21, 2021, 05:08:47 PM »
Do you have a multimeter and know how it is used?

Do you have the wire diagram/schematic?
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

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Offline bryanj

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Re: CB500 Electrical Issues
« Reply #2 on: May 21, 2021, 09:15:40 PM »
Battery terminals tight?
Ground connection tight and not painted?
Fuse box termials good?
Starter cable trapped and grounding?
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!