Topic: Green Wire, No Insulation--Yikes! Now What? Picture

[Popwood]

Horn stopped sounding on my '75 750K so was checking connections, tracing wire. When I looked closely under the left side cover was looking at the green wire going into the multi-connector and the connection looked like crud. Looking more closely the insulation leading into the connector didn't look good. Then I started unwrapping some of the electrical tape on that part of the harness and most of the way up to the main harness the green wire insulation looked fried, mostly off the copper and stuck to the tape. See photo below.

The bike otherwise has been running fine. But now what do I do? Is there a way to remove this wire and connector from the multi-connector? I'd at least like to get some heat shrink wire insulator on it as a temporary fix. Is it likely this entire length of wire is like this? All the other wires in the harness look fine. Please help!

[750goes]

I'm a little bit confused - that wire does not look green - but seems to have been damaged from an oversupply of current passing through/along it.

Can you check your wring diagram - and see what colour that wire should be.

Also if your GREEN Earth wire is burnt back into the harness - it is likely that your battery polarity has been reversed at some time... then you also need to check your reg/rec as well - this could be where that damage came from

[Popwood]

Thanks, 750, the insulation that was on the wire was most certainly solid green. What you see in the photo is the bare copper strands. I picked up this bike in July and it has been running just fine, very reliable. On my watch, the polarity has never been reversed. But then there are those POs, and when I got this bike that PO had a very "creative" wiring arrangement hooking up his Windjammer fairing electricals. I'm gonna assume the everything is functioning as it has not presented any problems, but my concern is the condition of this once fried wire, poor insulation on it and what to do from here.

[TwoTired]

The terminal can be released from the connector.  The terminal has a barb on it that needs to be depressed, which allows extraction.  There is a (sleeve tool" made for removal.  But sometimes an exacto blade can be inserted for the barb defeat.  Some cleverness is required without the prescribed tools at hand.

The green wire insulation burn was most likely caused by a battery connection with reversed polarity.  This makes all the diodes in the rectifier go into full conduction and presents a direct short between the Red and Green wiring.  This often damages the red wire insulation, too.

[Popwood]

So what should be my next steps?
Given that the bike has been running reliably nearly every day for 4 to 5 months, the regulator/rectifier is working as well as other component parts. So is it now just a wiring issue-- compromised wire/connections conditions. Am I looking at replacing the wiring harness or does one unwrap the harness tape, replace the offending wires, re-tape and done?

As an update, I used electrical tape to insulate the bare copper on the section of harness leading into the multi-plug. Started up without issue (but the horn still doesn't sound-- assume that's a separate issue.

Auto parts store guy suggested I could remove the offending wire connection from the multi-plug. Tried without success using a stiff, relatively small gauge wire and also tried a nut pick. Wondering if the heat from the reverse polarity may have made this removal all the more difficult? Thoughts?

Thanks, Two Tired. Always know I have good advice from you.

[Salmonser]

Hey there. My thoughts. Unwrap the tape back from the frayed end a couple of inches. Cut off all the burnt wire, then slowly strip the insulation back from the once frayed end until you've got good clean copper.  Solder in a short piece of wire. Heat shrink. Crimp on a new blade and put it back into the connector.  You could do a resistance test through the circuit if you wanted.

Check your fuses and battery connections.

[TwoTired]

I repaired a 76 CB550 with similar damage.
I replaced all the wires in the harness that had damaged insulation, including the green wire.  Wires laying next to the green wires had melted insulation, too.
I unwrapped the harness to find all the damage to be repaired.
I used garden twist ties at all the harness breakout points to keep the harness in its proper shape.
Wires with damaged insulation were section replaced, butt soldered, and shrink tube insulated over the splice.
I was able to extract the pin form the connector.  It is possible that the connector housing can melt, too.  You can get replacements from www.vintageconnections.com.
.. well as the multi-pin tool for pin extraction.

I used bits from another Harness to rob the correct wire colors from.

The repair took about a day of leisure, plodding work.  It was a nice day to sit and watch out the garage door.  Fixing things is my hobby.

Cheers,

[fastbroshi]

   You might need to unwrap the whole harness to trace how far back the crispy wire goes, not just a couple inches.  It would be a shame to do all that work unwrapping a section and soldering in a good connector to just have the still damaged portion continue to overheat the wires next to it until your bike stops running or worse.

[Hush]

I did the same as TT for my harness, just unclipped the whole thing from every connector and lifted it away from the bike, unwrapped it like an Egyptian mummy and replaced the bits that looked cooked.
Rewrapped it in insulation tape (regret not using something a bit fancier now) and it has not failed me in over a year.
The headlight connectors inside the bucket are as per usual the biggets #$%* but I marked them with a fine tip permanent marker and it all went back together fine.
By the way if that's your burnt orange 750 in your avatar it looks fine.

[Popwood]

Hush, the candy orange sunrise is my '75 550 and she's a beauty in great shape (just about 9000 miles). The wiring problem I describe here is with the '75 750 I also have, what I think of as the beast-- i.e. beauty and the beast. Winter's a comin' in this part of the world so I have time to sort our the wiring problem and rebuild what needs it. My only disappointment is I was planning on riding the "beast" over the winter (we only get a few possible days between Dec. and end of Feb.) so I was thinking of keeping the 550 laid up in the garage over winter to keep her out of salty slush melting snow piles. Maybe I need to rethink my plan. 

Thanks TT as I now see what needs be done, a plan of procedure. Fixing things my hobby, too. And sometimes feels like my day job as business is so challenged these days. But at least this winter I'll have a better place to work. My son and I have taken on some space that's real cheap in a run down part of town. We have a two car garage and are putting a woodworking shop (my other passion) on the second floor complete with freight elevator (to hoist bikes into a heated area as needed). We're rehabbing some other bikes so it's shaping up to be a really great situation. Bikes, furniture making and sharing it all with my boy. Times are tough but life is good.

[Salmonser]

 Know your electrical tests. Unwrapping a whole harness is a pain in the rear. And Super 33 is expensive.

[Jerry Rxman Griffin aka MuthaF'er]

I use a jumbo size paper clip to make a tool for removing the terminal spade from the connector.

Open up one end of the paper clip. Lay it on an anvil or smooth concrete garage floor. Hit it with a hammer until the end flattens enough to insert into the connector and push down the barb. Pull out the wire.

[bryanj]

There is another possibilty for melting,

If the ground wire does not have a good clean connection at the frame all the starter current goes via the small green wires and melts them

[Spruce]

There is another possibilty for melting,

If the ground wire does not have a good clean connection at the frame all the starter current goes via the small green wires and melts them

This is my working theory for fried green insulation on my '75 750K.  A few different lengths of ground wire were involved but all were in the same area.  Some PO connected the ring-terminal for a ground wire to the rectifier mount bolt.  This bolt is rubber-mounted and insulated from the frame.  I relocated the ground to the seat-latch mounting bolt.

I bought green wire in a couple of sizes at NAPA and got the male and female spade pieces for inside the plugs from my local mechanic/boneyard/raconteur.

EDIT:  Oops.  I don't think that all the starter current went through these wires; I think it was all the charging current.  That's based on which ground connection was insulated instead of grounded.

[Popwood]

So I last reported I cleaned up the connection and taped the fried wires, all this being a temporary fix. This week the bike has been running fine, if not better than ever.

I've noticed my indicator lights on the handle bars (oil, neutral, etc.) are brighter than ever. And mysteriously, the horn started sounding today on my way home from work. Didn't work on the way in this morning.

Does the bad wire, now improved, now have less resistance or something that improves power output? If so, that would be a big motivator the replace the whole length of wire sooner rather than later; not to mention cleaning up any number of electrical connections.

And just want to mention that the ride in today at 32 degree temp was quite comfortable on a sunny day. Better gloves and an improved angle on my windscreen leads me to conclude I'll get a lot more miles in this winter vs. last. Hoo-Rah!!

[TwoTired]

When the wire cooks off, it not only loses it's insulation, it loses its protection from oxidation, as well, which eventually makes it thinner.  Further, the wire to terminal crimp becomes degraded, too.
All, this leads to the wire end to end connection gaining resistance to current flow and resulting in voltage losses.

That green wire carries both accessory loads as well as power to charge the battery.  It's in your best interest to make it all that it can be.

[Popwood]

Thanks, TT. I was planning on replacing the fouled wire anyway, but all the more reason to get on it sooner.

But wonder, I'm thinking this horn working, not working, has more to do with a loose connection than the condition of this wire. I've checked the leads from the wires exiting the horn and those are fine. I was thinking this is a problem with a connection in the headlight bucket. What do you think?

[TwoTired]

I don't know what you knowledge base of electrical theory is.  So, don't think I'm trying to be insulting, ok?

You can think of circuit paths like a divided Highway.  Current travels up the road to the destination and then back on the other side to the origin.

If electricity can't get back "home" (the origin). it won' leave.  Wiring, like many roads, have bridges (interconnects).  If any of those are washed out or broken, in either direction, the current cannot make trip.

The bike's wire diagram is your road map.  While it does not specify terrain, it does describe the roadway needed for the journey.

Your job is verify that all the roadways are intact.  Once, the roads are complete and connected, there is no holding back on the electrical flow, as long as the end device demands it.

Does this help?


If you have not yet checked the wire diagram for your bike, do so.  It will describe the wire colors used in the circuit path between battery and horn.   If they do go into the headlight bucket, then check to make sure those wire colors are joined with a connector.

Cheers,

[Popwood]

TT, thanks for the roadway analogy. You lay it out like the Zen Master.  That helps a lot. And as for insults, none intended, none taken. I know a little, maybe a bit more than some, but still a lot to learn. I have studied the wiring diagram (actually a very helpful one for this 750 on the "old man honda" site in full color) and it is helpful, but, as you say, it doesn't describe the terrain, so maybe the loose connection is in the bucket, or maybe not. I will track it down. And I will replace the compromised ground wire.  Thanks again for your sage advice.

[TwoTired]

I will caution you that the Clymer diagrams are a general guide only. Often not specific to your particular bike.
I recommend you use the diagram found in the Honda Shop manual supplements.

Cheers,