Troubleshooting electrical issues by smell

[Boog]

If you recall about 20,000 miles ago, my front bearings had seized up. I could smell an electrical hot/burning smell but couldn't figure out where it was coming from. The dealer found it and fixed it.

You may also recall I mentioned my auxiliary lights quit working about 5 months ago. I replaced light bulbs, relay and verified the fuse was good. I could not find anything visually wrong with the switch but suspected it was the problem. Well, it wasn't the issue. The sub-harness coming off the main harness has melted. The part is on order now. But leading up to the failure, I do remember smelling an electrical burning smell. Funny, it went away after the aux lights quit working.

The dealer mechanic thinks the circuit overloaded (too much resistance) and not that the engine heat caused it. Still, I do sit in traffic on very hot days in the summer and wonder if that is an attributable factor.

Now that the bike is broke in some, (50,000 miles) I am starting to learn it's orders and what they mean; just food for thought...

 

[Mike Rocket]

If you recall about 20,000 miles ago, my front bearings had seized up. I could smell an electrical hot/burning smell but couldn't figure out where it was coming from. The dealer found it and fixed it.

You may also recall I mentioned my auxiliary lights quit working about 5 months ago. I replaced light bulbs, relay and verified the fuse was good. I could not find anything visually wrong with the switch but suspected it was the problem. Well, it wasn't the issue. The sub-harness coming off the main harness has melted. The part is on order now. But leading up to the failure, I do remember smelling an electrical burning smell. Funny, it went away after the aux lights quit working.

The dealer mechanic thinks the circuit overloaded (too much resistance) and not that the engine heat caused it. Still, I do sit in traffic on very hot days in the summer and wonder if that is an attributable factor.

Now that the bike is broke in some, (50,000 miles) I am starting to learn it's orders and what they mean; just food for thought...

Very worrying. A bike of this age should not have problems like this.

 

[Grumpy Ole Codger]

Hmm.... not sure on that explanation. How can a circuit overload or have too much resistance upon it if it has been designed for the purpose you were using it for? Break down in insulation through heat perhaps? Generally, a circuit only overloads when you attach items which are not intended to be there or outstrip the load capability of the said circuit. What fuse rating were the aux lights on and is it a separate circuit or are there other items plugged in to the same circuit? Just a few thoughts as seems odd?

 

[EasTexRIII]

Boog, did you replace those bulbs with higher watt, aftermarket bulbs?
I did that on my 05 standard on the 2 headlamps (before I replaced the assemblies with LED's)
A few weeks later I started smelling that "electric burn smell" - the plug ends were melting from the higher watt bulbs - I replaced the plug ends with high heat resistant, aftermarket ends made out of "bakelite" or ceramic
Fixed it

 

[Grumpy Ole Codger]

Boog, did you replace those bulbs with higher watt, aftermarket bulbs?
I did that on my 05 standard on the 2 headlamps (before I replaced the assemblies with LED's)
A few weeks later I started smelling that "electric burn smell" - the plug ends were melting from the higher watt bulbs - I replaced the plug ends with high heat resistant, aftermarket ends made out of "bakelite" or ceramic
Fixed it

There I rest my case

 

[TURBO200R4]

i had replaced one headlight with daymaker and later left ignition switch on about 5hours later only the daymaker was working and the headlights was weird when hitting hibeem switch.
the problem that it melted the headlight connector (on the ground side). i just spliced in a car connector and has been fine since.

 

[Boog]

Very worrying. A bike of this age should not have problems like this.

I suspect I may be the reason as I ride the bike more than I clean it. Grime has been my bane for some time now and it is everywhere on the bike including under the tank. Maybe, it is causing the resistance.

Hmm.... not sure on that explanation. How can a circuit overload or have too much resistance upon it if it has been designed for the purpose you were using it for? Break down in insulation through heat perhaps? Generally, a circuit only overloads when you attach items which are not intended to be there or outstrip the load capability of the said circuit. What fuse rating were the aux lights on and is it a separate circuit or are there other items plugged in to the same circuit? Just a few thoughts as seems odd?

I can't remember what fuse it is off the top of my head but it is the factory correct rating. But I always thought that if too much resistance was building up, the fuse is there to stop in by burning out. That didn't happen in this case.

Boog, did you replace those bulbs with higher watt, aftermarket bulbs?
I did that on my 05 standard on the 2 headlamps (before I replaced the assemblies with LED's)
A few weeks later I started smelling that "electric burn smell" - the plug ends were melting from the higher watt bulbs - I replaced the plug ends with high heat resistant, aftermarket ends made out of "bakelite" or ceramic
Fixed it

The bulbs are the exact same as what came with the bike. I have not put in any higher wattage bulbs to date.

 

[Grumpy Ole Codger]

Dirt will not cause the resistance unless there is corrosion of the actual connections. If you haven't changed the lamps - higher wattage = higher current draw = greater load on the supply cable - either faulty wiring from manufacture or heat over the years has broken down insulation on cable resulting in melting. Why the fuse didn't blow...a mystery!

 

[TURBO200R4]

every connection causes more resistance as the connection gets older heat at the connection causes the connector (blade type) to open up so the resistance gets worse till it melts down.
that is why they have been saying to crimp the terminals and apply the grease(cannot recall the name) to the terminals to keep out the weather and dust and moister.
the fuse is there to protect the circuit some times it works and sometime it doesn't.
if the connection is bad it will do a melt down before the fuse melts
example the ignition switch melts the soldier before blowing the fuse

 

[Grumpy Ole Codger]

The main idea of the fuse is to protect the circuit or wiring so if it isn't blowing there is something wrong with the fuse or its rating. Dielectric grease is used on electrical terminations/connections and is ridiculously expensive! Normally acquire it by the bucket full at work thankfully!