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Author Topic: lights dimming  (Read 740 times)

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Offline lefty2023

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lights dimming
« on: October 07, 2010, 07:49:23 AM »
hello, i have a stock 77 cb550k.  lately my bike has had a hard time having enough battery power to turn over, i can always kick start it.  the battery just goes dead.  also when the bike is at idle the headlight, brake light and turn signals dim down a lot but when i rev the bike up lights come back on.  recently ive put a new flasher relay in would this have an effect on the rest of the electronics.  is this a battery issue?? charging issue?? the battery is less than 1 year old
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77 cb550k and 77 cb550f

Offline bryanj

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Re: lights dimming
« Reply #1 on: October 07, 2010, 08:04:47 AM »
The charging system on these bikes is marginal and only just keeps up when lights are on or doesn't if a high wattage/Halogen headlamp bulb has been fitted.

As the lights brighten it sounds like yoour charging system is working but a full charging check asper the manual using a good digital multimeter woould be an idea as would externaly charging the battery
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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).

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Offline flybox1

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Re: lights dimming
« Reply #2 on: October 07, 2010, 08:08:03 AM »
you need to start with a fully charged battery to run tests and get accurate results.

lots of electrical diagnosing how-to's here:
http://forums.sohc4.net/index.php?topic=1012.0
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'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

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Offline cobra2411

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Re: lights dimming
« Reply #3 on: October 07, 2010, 08:55:41 AM »
How old is the battery and if it's not a sealed unit is it filled up?

Also check for dirty connections that can be causing loss.
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Offline Skunk Stripe

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Re: lights dimming
« Reply #4 on: October 07, 2010, 01:17:10 PM »
I would second Cobra's advice with the connectors. 30+ years is not kind to less than stellar connectors.
Might I suggest also swapping your blinkers to led bulbs with an electronic flash unit along with swapping the tail light.
The led bulbs are pretty close it as bright if you get a quality unit and will save some wattage that can go to your battery.
Some people also swap the indicator lights in the gauges too.
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