Topic: Melted wiring - Help me find the cause?

[Blitzburgh207]

So I just got my project rideable and went on a 300mi trip this weekend.  I get home fine and take a short trip to my buddy's camp the next day; go to leave, and I made it about 100ft up the road.  No headlight so I picked up the seat to check the fuses only to find this mess of melted wires.

I tried to take pictures to show you guys as best as possible.

This is what it looks like inside my "tray":

Wires to rectifier are the worst:

The wires to the starter switch are cooked too.

Fuse connection looked fine and no blown fuses oddly enough... EDIT: ALL 15A FUSES

And the ground to the regulator burned to the point of snapping it



And wen't up to the coils but that's as far as the short went it looks like? no melted wires in the headlight bucket or harness past the coils.



Is my new ground from the battery to motor too long now? or too heavy?
It goes from here on top of the arch at the back of the frame

to the motor mount


So what do you think?
Fuses aren't blown and the wires to the fuses didn't even look hot.  The wires to the rectifier are really bad, the wires to the stator are pretty melted too, and pretty much every ground wire is toast up to the coils.

I bought a new wiring harness today as well as modern regulator rectifier unit.  I'm going to replace the whole thing because the PO spliced a bunch of the wires in the headlight bucket to lengthen them apparently, and now the back half is effed too.  So how can I prevent burning up my new harness like this one? ...I know I must have done something wrong...it worked fine before my "rebuild" lol

Thanks guys.

[Blitzburgh207]

Oh yeah and the battery was pretty hot.  Will I need new coils?  Ugh this sucks 

[LesterPiglet]

Possibly the wires behind the chain cover got chewed by the chain? Check in there for torn wires.

[lucky]

Think about this....

Quote:

"So I just got my project rideable and went on a 300mi trip this weekend.  I get home fine and take a short trip to my buddy's camp the next day; go to leave, and I made it about 100ft up the road.  No headlight so I picked up the seat to check the fuses only to find this mess of melted wires."

The problem may not be anything you did or did not do.
The voltage regulator did not regulate the voltage properly.
Or there was a short to ground.
The fuses are there to protect the system.
How many amps were those fuses? Should be two 7 amp fuses and one 15 amp fuse.
Are they correct???

There is nothing wrong with your ground wire to the engine.

But you also need a ground to the engine to the frame.
Do you have a ground from the engine to the frame?
Just the steel frame is not good enough.
It needs to be a copper wire to make an easy path.

The headlight wire may have gotten shorted and of course when it gets hot it will melt into other wires.
The shorted headlight is what caused the problem. So we get back to the same question....How many amps was the headlight FUSE??

[Spanner 1]

Not sure we have the full story here... .... the bike will run with the battery installed backwards ( reversed polarity ) but the rectifier will short-out PDQ and melt wires as photos show.... and fuses wont blow as headlight/ignition/taillight circuits are not overloaded ( and will work fine if wired in reverse ). The clutch diode might melt some wires too, btw...... all = . The bike might run for 100 feet or so until the dead short on the battery pulls the voltage down PDQ below enough to make the plugs fire.
If you unplug the rectifier and pull the clutch diode out of it's holder, you can connect the battery backwards and everything on the bike will work as normal...no burnt wires or anything and you can ride away no problem until the battery dies as the battery won't charge.... , but otherwise no damage.

[scondon]

I'll let the electrical gurus provide the volts/amps and what not, but in plain language...the stator cranks out a lot of volts to send back to the battery to charge it. The regulator determines how much the battery needs and asks the stator for it.....

From your description and the pics of your modified electrics I would guess that for whatever reason your regulator has been asking the stator for full power all the time and that power has not been all making it to the battery. Your electrics "tray" may not be properly insulated from the frame, and any bare wire from your stator/regulator/battery lines could be arcing to it causing a hot mess. Also, LesterPiglet mentions behind the chain cover as that's a common spot for the wires to get chewed up.

Modified routing of wires and harness can also be suspect if they route around any sharp edges. Vibrations caused by normal riding can cause wiring to be sawed right through by any square edged piece of metal . When you get the new harness and do your rewiring keep this in mind to avoid any future trouble.

I have very nearly welded a poorly insulated battery box to the frame by riding with a frayed wire that was arcing to an uninsulated mounting bolt, and I didn't pop a single fuse. The smell and my hot seat gave it away.

[Spanner 1]

SC... have you looked at the pics ?... 'scuse me but that devastation can only be achieved by a reversed battery OR a charger connected in reverse. Any of the circuit wires are protected by the 3 fuses ( seen in one of the pics. ) and could not burn as shown  and why would they  all together ?
Poster needs to fess-up to a reversed battery or reversed (car) charger  applied to the bike.....

[bollingball]

How many amps were those fuses? Should be two 7 amp fuses and one 15 amp fuse.
This is not correct  Tail light is 5a
Ken

[bollingball]

So how can I prevent burning up my new harness like this one?

Don't hook up the battery,charger or jumper cables backwards.
Ken

[Blitzburgh207]

Well unless the battery is stamped wrong, I didn't hook it up backwards.  You can also see this in the picture of my ground wire.  I tried to insulate the tray from the frame by using the "insulators" from the factory box - however I will admit that in my haste to ride, I didn't mount the regulator on tabs or anything and it was just sitting in the bottom of the tray (opposite of the oil tank - I didn't know if the heat would mess it up).  Could the metal regulator on metal tray short it?

The battery was nearly dead last week because I left the key in the "on" position, but it still had enough juice to kick start it, and I never jumped it.  I put the battery on my step-dads trickle charger, 1.5 amp I believe, and it wouldn't charge it or even turn the light on - I thought maybe I needed a different charger for my "sealed" battery.  I didn't try reversing the feeds - red is always pos and black is always neg right?  Is it possible it could it be stamped wrong??  Seems unlikely.... However, the terminals ARE opposite of my old battery and others I've seen...

But after riding down to Portland, about 130 miles or so, it had enough charge to use the starter.  So I feel like it was charging properly then?

Also - I didn't have the right fuses.  They were all 15 I believe  I know it was stupid - that's all I had left and I meant to stop at napa or something but spaced it...

Should have been: 5a tail light, 7a headlight, 15a main per the fuse box cover and manual

And I can't check the wires from the stator right now as I'm at work.  I will when I get home though.

Thank you all for the help!

[Blitzburgh207]

Not sure we have the full story here... .... the bike will run with the battery installed backwards ( reversed polarity ) but the rectifier will short-out PDQ and melt wires as photos show.... and fuses wont blow as headlight/ignition/taillight circuits are not overloaded ( and will work fine if wired in reverse ). The clutch diode might melt some wires too, btw...... all = . The bike might run for 100 feet or so until the dead short on the battery pulls the voltage down PDQ below enough to make the plugs fire.
If you unplug the rectifier and pull the clutch diode out of it's holder, you can connect the battery backwards and everything on the bike will work as normal...no burnt wires or anything and you can ride away no problem until the battery dies as the battery won't charge.... , but otherwise no damage.

What is PDQ?
The clutch safety is gone altogether.
Is the diode the silicon?
Nothing was changed (as far as me physically changing anything - something could have been cut or otherwise damaged) between my 130mi Friday, 170mi Saturday, 20 miles to camp, and 100ft from camp Sunday.

Would the bike have run so well so long if something was reversed this whole time?

[Blitzburgh207]

Would the bike have run so well so long if something was reversed this whole time?

Ps: Not being a smartass here. Serious question 

[LesterPiglet]

PDQ= pretty damn quick.

[Blitzburgh207]

PDQ= pretty damn quick.

LOL!! ...I thought it was some charging system component I didn't know about lol 

I'm the first to admit my first grade electrical competence lol

[lucky]

Quote:

"Also - I didn't have the right fuses.  They were all 15 I believe   I know it was stupid - that's all I had left and I meant to stop at napa or something but spaced it...
"

Case closed.

Well look at it this way you did not get hurt. There was no fire. You were not stranded in freezing temps ,and you bike is going to get a new upgraded electrcial system!!

[Blitzburgh207]

Case closed.

Well look at it this way you did not get hurt. There was no fire. You were not stranded in freezing temps ,and you bike is going to get a new upgraded electrcial system!!

Well not exactly case closed... but I am very thankful that I didn't get hurt, no fire, and I wasn't stranded.  The neighbors did give me a funny look though when I coasted back down the hill lol.  ...it's a hybrid 

[scondon]

SC... have you looked at the pics ?... 'scuse me but that devastation can only be achieved by a reversed battery OR a charger connected in reverse. Any of the circuit wires are protected by the 3 fuses ( seen in one of the pics. ) and could not burn as shown  and why would they  all together ?
Poster needs to fess-up to a reversed battery or reversed (car) charger  applied to the bike.....

  To be honest I have never seen wires quite that melted, nor have I experienced the devastation of a backwards connected battery firsthand.........yet   I can only recount what happened to me and how it created quite a bit of heat, enough to melt metal, and did not pop the fuses. That was however confined to the location of the exposed wire and didn't travel throughout the harness.

   Having dealt with my own "modified" wiring harness I pretty much stopped at the pic with the metal electrics tray full of melted bits and thought "hmmmm....that looks familiar"

[lucky]

Case closed.

Well look at it this way you did not get hurt. There was no fire. You were not stranded in freezing temps ,and you bike is going to get a new upgraded electrcial system!!

Well not exactly case closed... but I am very thankful that I didn't get hurt, no fire, and I wasn't stranded.  The neighbors did give me a funny look though when I coasted back down the hill lol.  ...it's a hybrid 

Yes it is a hybrid. It uses oil AND gas.

[Spanner 1]

The meltdown didn't happen in the 100 ft. 'last ride' before it conked-out, it happened at some previous charging incident and finally 'gave-up' that particular day..... A car charger could damage the rectifier, shorting-out say 3 of the diodes and allowing a partial short across all the ground paths = overheat/melt of the wires AND low charging rate( as reported by poster.... battery was high enough after 130 mile ride to electric start )...... so, maybe the battery/ charger was not reverse wired , simply the too high voltage from a 10A charger partially fried the rectifier.... my money's on that 
Note:   SOHC rectifiers can short-out when a car type charger is connected in reverse AND even when connected correctly as the small load of the bike battery will allow a high voltage to the rectifier ( more than 17v or so may blow it ).

[Blitzburgh207]

Hmm.  So somehow I messed up the regulator?  So with the new harness and new reg/rec I shouldn't have this problem again?  Well, obviously with proper routing (no sharp edges, pinch points, etc.), proper fuses, solid grounds, etc..

Is the battery screwed now too?  I'll look up how to test it in the manual, but it's not stock so will it be different?

Oh, and the battery was not in the bike when I tried to charge it.  So the charger I attempted to use wouldn't have affected the charging system on the bike right?

Thanks again everyone.


Oh yeah...

  To be honest I have never seen wires quite that melted

....#$%* lol

[Spanner 1]

Unfortunately no, even with the battery out of the bike the rectifier is always connected to the + and - wires.
So scenario of too high voltage from charger still applies  .... and in fact even more so as without the 'load' of any battery very probable the rectifier got fried just as soon as you connected the charger.
I think this is 100% what happened.....

Lesson is; if you must connect a 10A charger to your bike , battery installed or not, you MUST disconnect the rectifier plug BEFORE connecting the charger.... better lesson would be never do it 

[Blitzburgh207]

I'm confused now.  The charger was never "on" the bike.  Its fixed to the wall above my bench like 20 ft away.  I took the battery out, put in on the bench, hooked the leads up to it, and the light on the charger did not come on to say "charging".  I put the leads to my multimeter on the battery terminals while it was hooked up to the charger and it only read about 4-5 volts as far as I can remember...  24hrs later it was the same and I took it off and put it back on my bike.  It would not turn the starter over but was enough to kick it.

Should I have been looking at amps?

[Spanner 1]

Oops ! ... I thought you had connected the charger to the + and - wires of the bike, without the battery installed ( to try to start the bike directly off the charger )..... But lesson about that still stands !!
So, at some time previously I think you had connected the car-type charger to the bike, battery installed, cables not reversed ?

[TwoTired]

I didn't try reversing the feeds - red is always pos and black is always neg right?

No. 
Colors are contextual in "electron speak".  They are "assigned" by the designer. (Actual electrons are color blind.)
Honda, the designer, has defined Red as unswitched battery POS connection, and Green as unswitched Battery NEG connection.
BLACK = switched (key switch) battery POS connection.

If you try to marry Honda assignments with another designer's (including you) assignments, you can easily get the random spark, smoke, flame, and part distortion from heat.  Electrons see and respond to pathways rather than color.

If you truly want to find cause, you will tell us what wire diagram currently applies to your bike.  Otherwise, it is what it is, learn to live with it...
or not.

Cheers,

[Brantley]

First off, Radio Shack sells a pocket calculator sized digital multimeter for around $15, last I checked. Get one. It's totally adequate for anything you'll need to test on an SOHC, including whether your Chinese AGM battery is mislabled positive and negative (if the red lead's on positive and black's on neg it would, as an example, read 12.9; reversed it would read -12.9). Second, the wiring from your alt cover (three yellows, a green, and a white) is connected to a short harness with bullet connectors beneath the sprocket cover which then connects to a block connector to the main harness. Lots of connections for a sorta important assembly... If any get corroded, cut or unattached it creates lots of heat with not much place to go except out. Like thru it's plastic jacket inside one of those harnesses, then thru the one next to it, ad infinitum. Once you have positive and negative wires shedding their jackets from heat and resistance that are cozied up next to each other you start to have problems. If you detach the ground to the voltage regulator with a battery installed ALL of your grounds fry in an instant (at least on my '71 Super Beetle 20 years ago-oops). Reverse the polarity to the reg- that starts some pretty quick burning, too. You may not have done these things, but hot wires may have for ya. By the way, Advance will load test your battery to tell you if you have a bad or shorted cell. I had a Chinese AGM battery a few years ago that read 12.9 volts on the meter and dropped to 9ish when the key was switched and bottomed out when the start button was pressed. It was 6 months old.