Topic: Horrible Wire Gremlins 74 750!!! Headlight!!!1

[Tews19]

I had tp replace the wire harness for my 74 750... I installed it and have everythingn hooked up correctly...

At least I think so.... Weird thing is the headlight does not work.... I know it works as I removed it from another bike that works...

I hooked up the blue from the headlight itself to the 2 blues that are located in the harness....

Hooked up the green with another ground from the harness and the white from the headlight to the white in the harness.... Absolutely nothing................

To make things more complicated.... the left side turn signals flash properly but the right side stays on and doesnt flash.... The only way to even have the front turn signal to work on the right side is to have the solid light blue wire connnected to the wire harness solid light blue and the light blue wire from the turn signal connected to a ground wire from the harness........

I should mention there are 3 brown wires that come from the harness that are not connected to anything. I actually had to dig them out of the black wrap... Looks like they came from the factory as spares... Not sure... A

Any insight would be great!!!!!

[Tews19]

The 3 brown wires that are not being used are a brown with blue stripe pretty sure this is to be connected to the buzzer with the lone black wire not being used. Brown with red stripe and a brown with white strip. There is also a single black wire from the main harness not being used nor is a solid black wire able to be plugged into it.
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[w1sa]

Have a look at the wiring diagram...you will see that both the Blues (HB and HB Indicator) go back to the Left Hand Sw control (via the single HB Blue wire)...they (and the Low Beam white wire) are fed fused/sw 12v via the Br/R wire at the Left Hand H/L switch control....then Br/R  back to the fuse...and from there, back to a Br/R  - Br/W junction in the harness,... from there via Br/W andbullet terminals  back to the Right Hand Sw control and then Bk wire back to the Main (Key) Sw.

The Buzzer uses a Bk wire and a Br/B as you suggest.
 

[Tews19]

Thanks for the detailed description. I will follow your explanation and see if that will fix the issue.
You asked if I only have H or L beam. I have none as of right now.

[Tews19]

So there is only one brown\red wire from the left hand control. Which one does this hook up to?

Then from the control there is one brown\white wire. Where does this hook upto?

[LesterPiglet]

Brown/white is for your gauge lights, I'm not sure about the other.

[Lars]

Have you checked out the headlight fuse???

When it comes to the front winkers, they have two wires going from the winker and into the bucket. One is for the winker, the other is for the all time stay on light in the winker used in US. I think both wires are black, but one marked with an orange label goes into the orange wire connector. Same With the black and blue. The other of the two winker wires is marked with an white label, to be connected to black for constant power to the winker light. Not allowed over here.

Brown and red should be hooked up to another Brown and red from the main harness.

Brown and blue is for the buzzer as mentioned, together with a black for power.

Here is something useful, an interactiv wiring diagram from oldhondaman: http://oldmanhonda.com/MC/wiring750K1.html


Lars

[Harsh]

Is the main wiring harness new?  If so there are some wires you will have to jumper to get things to work correctly.  Give me a minute to get the links for you.

[Tews19]

Harsh no need to look for the schematics. I got it all figured out.... Harness is a repro from ebay for 80 bucks.... I had to plug and play but she is good to go.... The right side doesnt flicker but I am done messing with her... All turn signals and headlight function now...

[Harsh]

Cool.

But just in case someone goes searching I will post the links here as well.  This has to do with repro wiring harness' and getting them to work correctly.

http://forums.sohc4.net/index.php?topic=110411.0

http://forums.sohc4.net/index.php?topic=110284.0

[lucky]

You need to learn how to use a multimeter.

Then you can know what the wire is being used for.

[iron_worker]

For whatever reason the reproduction harnesses bring the two brown/red wires all the way forward to the bucket instead of splicing them further back in the harness in as is suggested on the diagram I looked at ... could be to accomodate different variations from different countries I suppose.

The two red and brown wires basically are just connected to either side of the main fuse. It doesn't matter which wire receives power really ... but if you want to be consistent then pull the other two fuses and test to see which side of the fuse is powered and which is the load side (with no fuse the power side will have 12v and load side will have 0v). To be consistent, power should be sent to the same side of the fuse as the others ... but obviously a fuse will work either way.

I believe the power has to jumped with a short double male end wire from the extra solid black wire to one of the brown/red wires. Then, the other brown red will then be powered through the main fuse and connects to a brown/red (could be wrong on that) leading to the left hand control. This wire will then feed your headlight high and low beam ... depending on selector switch position... which would explain why it wasn't working in either position.

I also ended up with 2 extra wires on my harness ... from what I understand, they are just to make your headlight turn on when your bike is in "park" (key turned to the farthest position). I didn't hook these up. I believe this was a European requirement from what I have read.

IW

[Tews19]

Everything is good minus the right side turn signals. They work but wont flicker.  Also no running lights. If I get running lights then the turn signals dont work when being used. I dnt really mind as they function and make it legal.

[Lars]

Winker relay no good?

[Tews19]

It works. Left blinks perfect.

[bjbuchanan]

How is the grounding for the turn signal. Sometimes lights, with insufficient grounds, do weird things like that. System has black switched power to turn signal relay that connects to the light gray

Light gray goes in to headlight bucket, connects to handlebar switch gray. Output of switch is now blue or orange, not much else going on

Try finding a "sweet spot" that you can get the one light to actually blink. Inside of the turn signal switch there is a slider that carbon tracks and assorted grossness build up on and stop the proper contacts from working. Spray QD cleaner or something up in the switch thru the little hole in the bottom of the switch. Now try to see if you get anything to work. If it blinks justtttt before it is all the way switched you have a dirty TS switch

[Tews19]

Grounding is good. I can get the left side to blink perfect. Its just the right side that stays solid. I unplugged the running lights due to the lights not working when I try to use the turn signals.

[iron_worker]

I believe a build up of corrosion on your connections will increase resistance ... and once it has built up enough it will actually stop your lights from blinking at all. Make sure your connections are good.

Another thing to check is that you have all the correct type bulbs. Different bubs draw a different amount of current. Rear bulbs have a a single filament and front bulbs have 2.

That being said, also check that you have the running lights power wire in the front connected to the right filament. One filament will draw more power (signal filament) and one will draw less (running filament). Perhaps if you've reversed this on the one side then you aren't drawing enough power to flash it.

I think my bike has aftermarket replacement signals and both wires are just black so it's easy to mistake them.

IW

[bjbuchanan]

What is the condition of the handswitch? Also the wrong size bulb will make the thermal flasher work different. Maybe there is a different replacement bulb in the one lense. My money is still on the handswitch tho if it isn't verifiably in tip top shape

[LesterPiglet]

Have you tried using the left blinker wiring for the right blinker? This will narrow the problem down.