Topic: Wiring help please

[Cowboy48]

I started out the day with only minor wiring issues (if there is such a thing) such as I had high beam all the time, the turn signal indicator came on solid if the headlight was on, and the headlight stayed on even with the fuse pulled out.  Ok I figured, I have some headlight wiring to deal with but everything else worked as advertised.  The problem started after I removed the headlight to see if there was anything obviously wrong but didn't see anything so I put the headlight back in.  Then I had no headlight so I removed it again, wiggled the connector and the headlight returned.  At the same time I was also changing out the rear fender.  I had to clip off the connectors to get the tail light wires off so I decided to replace 2 of the wires that were worn.  While the fender was off I happen to notice that I had no neutral light.  I finished the rear wiring and put the new fender on with no problems.  Still no neutral and no turn signals.  Headlight works like it always did, the running, tail, and brake lights all work normal.  I'm pretty sure the problem is behind the headlight but it looks like a rat's nest in there.  I found 3 dead end wires with black tape around them, one of them striped like it had been pulled out of a connector.  It is brown with a blue strip and has no voltage on it.  Another dead end wire (brown with a blue stripe) has about 11vdc on it.  I think this is the disconnected turn signal buzzer wiring but I'm not totally sure.  A 3rd blue wire has no voltage on it. 

I have a color wiring diagram.  My main concern is just trying to figure out where to start.  I know it's not possible for any of you to fix the problem from cyberspace but can anyone offer advice as to how to begin?  Any commonality between the neutral light and the turn signals?  I can't see one in the diagram.  Should I consider a whole new harness?

Thanks a lot for any advice

[csendker]

Caution: I don't have a 750 wiring diagram, looking at my '75 550 diagram.

My turn signal buzzer supposedly came from a 750 (I have a 550).  It is currently in my hand (note: NOT on the bike, sounds horrible) and has a brown w/blue stripe lead and a black lead.  That one (coming from the loom side) should be 0V (dead) unless the turn signal is activated, then it's 'flashing' 12V. Is your buzzer still there?  It may be the dead line.  If your turn signal is lit solid, this would explain 12V solid to the other one.  Stuck turn signals can be incorrect wiring, a dead bulb or the wrong bulb (LED..) so there's not enough resistance for the flasher to work (swap out with modern flasher).

Headlight: The high beam lead is blue, low beam white, green for ground.  Remember there's a high beam idiot light that connects in; blue from headlight dimmer switch & blue from idiot light on one side & blue from headlight on the other side.  White from the headlight switch to white from the headlight.  If the headlight comes on when the fuse is pulled, it's wired into the wrong circuit.

My guess is that you won't need a new harness, just sort everything out.  Typically, like wires mate with each other.  Dissimilar wires are something to look for.  Dirty terminals will impact all of this.  Loose connections too.  I bought a bunch of the proper bullet connectors and found they work great.

[Cowboy48]

Thanks for all the info.  I will start fresh tomorrow and try to sort this out.  Where is a good place to get the proper bullet connectors?

[csendker]

I got mine from here --> http://www.vintageconnections.com/ Good company & quick delivery.

Or look here for more of just about anything --> http://www.sohc4.us/forums/index.php?topic=743.msg4704#msg4704

[Cowboy48]

Can someone comment on the picture that I posted please.  Is this typically how the wiring should look behind the headlight?  Is there any way to "tidy" this up any?

Thanks

[upperlake04]

looks very organized compared to mine   mine works fine

[csendker]

Mine: "Big Friggin' Rat's Nest"

And that's in the middle of my handlebar swap, so there's some more wiring missing.

[dusterdude]

actually,yours looks pretty good.

[Hyseman]

You should see mine, what a mess it is.