Author Topic: Turn Signal Oddities ('74 CB750K4)  (Read 1061 times)

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Offline Yoshimitsuu

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Turn Signal Oddities ('74 CB750K4)
« on: July 26, 2017, 09:04:05 AM »
Good morning all,

In continuing to prepare my bike for inspection I noticed that my right directional in the front was not working.
I looked in the service manual which prompted me to crack the headlight casing and expose the "rats nest" where
I found three unplugged bullet connector sleeves. In troubleshooting the lights I believe I found, I think,  the ground one
(clear w/ yellow) and I tried to see which of those bullet connectors would be the right one for the bike.
Both gave the same result:

1) With the wires not fed into the bullet connectors, the light obviously wont work. The rear directional on the right side will work though.

2) With the wires connected to either of the two bullet connectors the light will work but will not cancel if you switch the directional to the other side. With the switch on right directional, it works fine. On left directional, the front right light will engage along with the left directional lights.

So basically my options currently are having that light not work or having that light work but also lighting up when the other side of directionals are engaged. I tested the bulb and it does work so it's not a burned out bulb (which would have been a nice fix).

These are aftermarket turn signals so they are wired black, black/white, and green which is, from what I've gathered, similar to the stock wiring colors. I'm just kind of stumped and any help would be greatly appreciated!

Offline Yoshimitsuu

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Re: Turn Signal Oddities ('74 CB750K4)
« Reply #1 on: July 26, 2017, 09:11:02 AM »
Attached are some photos of the wiring. The first photo is a general view of the headlight area and shows the wiring of the light.

The second picture is a close up of the wires which shows that the black and white leads nowhere and that the black and green are the two bullet connections that I'm workinng with.

The third shows a connector where the left directional black wire is plugged into but there is no more space for the right directional wire. Pretty strange.

If there's anything else that I can provide let me know!

Offline CycleRanger

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Re: Turn Signal Oddities ('74 CB750K4)
« Reply #2 on: July 26, 2017, 09:44:20 AM »
You do know the front blinkers act as running lights and have dual filament bulbs?
The front blinkers should be lit when the headlight is on and of course the correct signals should flash when activated.
Do you have a wiring diagram?
Do you have a copy of the Honda Shop Manual or Parts List for your bike? Get one here:
https://www.honda4fun.com/materiale/documentazione-tecnica
CB750K5        '79 XL250s     CL350K3
CB750K3        '76 XS650      '76 CJ360T

Offline magnum56

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Re: Turn Signal Oddities ('74 CB750K4)
« Reply #3 on: July 26, 2017, 10:35:03 AM »
Did you at least look at the bulb before opening Pandora's box ... er ... headlight bucket ?

+1 on wiring diagram for your model bike.
 
And you can also try reviewing this link to an interactive diagram allowing you to filter out what you don't need.
 
http://oldmanhonda.com/MC/wiring750K1.html
'74 CB750K

Offline Yoshimitsuu

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Re: Turn Signal Oddities ('74 CB750K4)
« Reply #4 on: July 26, 2017, 10:43:33 AM »
I did check the bulb and it does work. I did not know that they were supposed to be running lights so that's news to me and will help me in my troubleshooting. I found a wiring diagram and after a break I'm going to take another crack at it. What was throwing me off was that the wires of the aftermarket lights are different colored than the Honda ones.

Also, thanks so much for that link. I've been playing around with it and found some things I didn't think of trying. Being able to remove things makes it way easier than the wiring diagram in the book which is a bit overwhelming. Thanks all!

Offline flybox1

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Re: Turn Signal Oddities ('74 CB750K4)
« Reply #5 on: July 26, 2017, 10:48:55 AM »
looks like aftermarket blinkers?
two wires out of the blilnkers...one to power, and the other to either  orange/white, or lt.blue/white.

If you want them back on as running lights....contact member Duanob.  He might still have a few of his trick 3-part harnesses available.
Takes your blinkers back to running lights in seconds.
'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

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mineā€¦"

Offline Yoshimitsuu

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Re: Turn Signal Oddities ('74 CB750K4)
« Reply #6 on: July 26, 2017, 11:11:26 AM »
I fixed them! The interactive diagram helped me see things a bit differently and then I looked at the other light to notice that there was a plastic plug on the other side for that switch as well. Thanks for the help :)




Offline magnum56

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Re: Turn Signal Oddities ('74 CB750K4)
« Reply #7 on: July 26, 2017, 11:24:08 AM »
I fixed them! The interactive diagram helped me see things a bit differently and then I looked at the other light to notice that there was a plastic plug on the other side for that switch as well. Thanks for the help :)


Good deal, I know it helped me isolate things as well.
'74 CB750K