Electrical burning smell, engine dies

[blaxmax]

Glad you found it- That Miles is a genius.

 

[Miles Long]

I would replace the blue wire from the Ignition Switch Connector (I.S.C.) to the splice point within the harness where the power is fed to the gauge, speedo and running lights, and then continue this new wire to the taillight connection.
The brown wire should be replaced entirely - from the ISC to the upstream side of the four-fuse box.
The red power wire should be replaced from the ISC to the downstream side of the main fuse holder, doing the "crimp" fix at the same time.
As for the ISC, you could eliminate it completely, OR used three individual insulated bullet connectors, staggered to not be in the same place, and individually shrink-tubed for added protection.
Also would be a good time to recondition the ignition switch itself.
Cheers!

 

[MaxMidnight]

Well dome Mr Mundmc for having a go! :clapping: I hope you feel a deserved sense of achievement. :biglaugh:

What Mr L said but check that there isn't any burning or melting within the ISC connector or that the adjacent terminals haven't overheated. When this happens they can loose tension which causes arcing...you know what follows!

I would replace at least the terminal within the ISC. These are retained within the block by a tang that sticks up and prevents the terminal being pushed back when making the connection with its mate.
If you look at a bare terminal you will see what I mean. A thin (watchmakers) screwdriver inserted above the terminal can be used to push down the tang and allow aforesaid terminal to be pulled out.
Can be a bit fiddly but just need to persevere.

Other wire replaced as described by Miles. Don't be tempted to use crimp connectors, soldering is a far better solution but remember to put some heat-shrink tubing into the wires before you solder. Alternatively use something like this.

If you are unsure about the soldering have a look at te many U Tube videos which show how it's done.

From what you have shown us the loom is salvageable. Replacement would be a last option and whist not difficult it can be extremely time consuming and frustrating trying to get it to fit the same as the old one.

Miles - re your one handed typing dilemma - try wearing the boxing glove on your non writing hand whilst 'inspecting' yourself.
Works every time...allegedly...I read somewhere....couldn't confirm this myself...obviously....

 

[blaxmax]

"I would replace at least the terminal within the ISC. These are retained within the block by a tang that sticks up and prevents the terminal being pushed back when making the connection with its mate.
If you look at a bare terminal you will see what I mean. A thin (watchmakers) screwdriver inserted above the terminal can be used to push down the tang and allow aforesaid terminal to be pulled out.
Can be a bit fiddly but just need to persevere."

I use precision screwdrivers for the front of the coupling and either hemostats or needle nose pliers at the rear and the trick is to move the terminal forward as far as you can then with the screwdriver holding the tang down and pull with the pliers to release. Then crimp, then solder.

The only thing i have ever felt through a boxing glove was someone else's nose.:boxing00:

 

[mundmc]

Sorry to ask an obvious question, but a few hours of searches has yielded nothing:
- What gauge should I use for replacing the blue and brown wire (I think 16awg)?
- Bigger gauge for the red wire (14awg)?
- Is there a part name for the locking disconnect that connects the key switch harness to the main harness? Should I replace it with something specific? (I'd prefer to isolate the key switch harness from the main harness).

Many thanks

 

[blaxmax]

The blue wire is 16 gauge and the red and brown are 14 gauge -a larger gauge wire is still going to carry the load.
The connector you are looking for is Connector Set Male and Female - Set YC2503
You will find it 4th down on the site below.

http://www.cycleterminal.com/250-connectors.html#SC250

 

[mundmc]

FIXED!!!

Keep in mind I'm such a novice that a year ago, when my puke tank was coming out the overflow hose, I just assumed the hose "came loose" from something, and I connected it to the drain hose from near the gas cap. So anything I've learned I have y'all to thank for it.

Step 1: fix the ignition switch and connection- all of the wires were fused together, and I suspected this may have caused the problem.
Before:

After:

(I had to deemed out part of the switch to make room for 14 gauge wires)

Next was replacing the blue wire that ran from the ignition switch to the tail light, as well as some of the other wires and connectors melted to it.

Before:

After: Well, no after shot.

That got the bike able to turn the ignition without blowing the main 30 amp fuse.

Since I was feeling cocky, I moved my rear turn indicators to the license plate so I could run saddle bags better.

Last, I soldered up "the splice" from, I think, the R/R, to the main power line (not sure the name).

Before:

After:

I'm pulling 0.4 more volts at 3000 rpm (13.6 -> 14), which I think is borderline acceptable.


Lastly, being really cocky, I threw in Blaxmax's cops, which was easier than expected. I gotta say, bike starts with less choke now, and I can put along smoothly in 1st without the "lurch" to which I became accustomed. Highly recommended upgrade.

All in all, thanks to everybody. Even when y'all argue, I'm still learning a thing or two from the discourse.

Hope this thread was useful to any newby's like me that run into similar problems.

Total cost of fix (including tools): $150
Total time (at novice skill):
Ignition switch re-wiring/ modding: 2 hours
Moving tail lights and re-wiring: 4 hours
Installing cops: 1 hour
Knowledge of how to fix again: priceless




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[Miles Long]

Good job, but by your description you replaced only the blue wire from the ISC to the taillight.
Do you have gauge, speedo and running lights? If not, see my last post.
Cheers!

 

[mundmc]

Good job, but by your description you replaced only the blue wire from the ISC to the taillight.

Do you have gauge, speedo and running lights? If not, see my last post.

Cheers!

Miles your post was very appreciated. On inspection, the only toasted wires were a) the blue from the ISC to the tail- there was a blue spliced to it under the airbox that was spared, and b) the tail lights. The brown to the fuses and the main red looked good.

Any major concerns about not following the rest of your fix?


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[Miles Long]

Miles your post was very appreciated. On inspection, the only toasted wires were a) the blue from the ISC to the tail- there was a blue spliced to it under the airbox that was spared, and b) the tail lights. The brown to the fuses and the main red looked good.

Any major concerns about not following the rest of your fix?

That splice that you found would be where the power is fed to the gauge lights and front running lights. I thought maybe you had not included this connection when you renewed the blue wire. But with all your lights working, guess I was wrong!
Looking at the wiring diagram, the only protection for the blue wire circuit is the main 30 amp. fuse, which may explain why this smaller-gauge wire took such a beating before the fuse finally blew. I would think a better arrangement would have been to channel the blue to the fuse box, and dedicating a 10 or 15 amp to protect it, before sending the current on it's way to the lights and taillight.
But I'm not a Yamaha engineer or an electrician, so I won't even guess as to the reason.
If the brown and red wire look good, don't worry about them.
Your problem does emphasize a characteristic of probably 80% or more of the electrical issues that have cropped up on this forum - the root cause is not devices, or the actual wiring, but connectors or splices. It's always good preventative maintenance to clean and lube with di-electric grease, any time the opportunity presents itself.
Cheers!

 

[mundmc]

You are totally correct about the blue wire splice, and I may put in a new fuse when I come back to it. I think it's odd, but the burn didn't continue "through" the metal splice connector. I got no idea why that is, but it saved me some work.

Thanks again regardless!


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