Electrical fire in the making?

[Corbeau]

This evening, with a cold beer on stand-by, I thought that I would de-winterize and ride to work tomorow.

The plan was simple: re-install the battery, start up my VTEC to warm it up, change the oil and filter.

Step one went as easily as it sounds. After hitting the starter switch for less than two seconds, I heard the familiar rumble of the VFR. Yeah, a bit rough for the first 10 seconds, but that's to be expected.

Then, I smelled smoke. (30 seconds after start-up) And 15 seconds later, I saw smoke, coming from somewhere in the front.

Dayum. I know it wasn't oil on the heads, because I didn't put a tablespoon of oil in the cylinders. And it didn't smell like burning oil, anyway. (Which also ruled out oil on the headers from the winterizing oil change) No, sir, it smelled of burnt rubber, which lead me to presume something electrical is frying.

Because I heard stories of mice nesting in airboxes, I lifted the tank and opened up the airbox and removed the a/filter -- nope, that's not the issue.

I started up the bike again, looking (and smelling) closely for smoke, and I confirmed it was not coming from the headers, but more behind the dash or something. I killed the engine after 60 seconds, because troubleshooting while waiting for flames is not my idea of fun.

Some of you might say "maybe a rodent chewed some of your wires" but I doubt that, given that my dog and cat patrol the garage.

What should my next step be? I kinda need to figure out what's frying where before the damage gets too expensive. Should I remove the LH fairing to check if the fuse box is smoking, or should I remove some body parts in the front before starting it up again?

Thanks in advance. PMS is not over for me.

One last thing: no electrical farkles were added this winter and I tripple-checked that the right wires (one for the GPS and one to a relay for the heated grips) were on the right terminals of the battery.

[HispanicSlammer]

Change your oil lately> oily smell or electrical smell? Check that dad gum main buss fuse that Bailey Rock is always talking about. It has a tendancy to burn up on the vtecs, lousy $2 dollar part can put a stop to your ride.

[Corbeau]

Change your oil lately> oily smell or electrical smell?  Check that dad gum main buss fuse that Bailey Rock is always talking about.  It has a tendancy to burn up on the vtecs, lousy $2 dollar part can put a stop to your ride.

<{POST_SNAPBACK}>

Electrical, for sure. Main buss fuse, on the RH side, behind that black cover in the front?

[Guest kerplode]

Electrical, for sure. Main buss fuse, on the RH side, behind that black cover in the front?

<{POST_SNAPBACK}>

IIRC, the main bus fuse in on the left, near the battery.

Best bet is to pull all the fairings and give all the harnesses and connectors a good visual inspection. If it was burning enough for you to smell it, you will definitely be able to see where it was coming from. Once you know what is burning it will be easier to figure out why it's burning.

[Guest]

Stay tuned folks

[kaldek]

Stay tuned folks

<{POST_SNAPBACK}>

I reckon you should remove all the fairings (front included), and also the seat. Fit a multimeter to the battery terminals and monitor the voltage.

Start the bike up and keep an eye on the voltage. Your voltage should not go above 15 volts no matter how hard you rev it. If it does, your Regulator/Rectifier is fried. The xtra voltage it's pumping out could be overloading something maybe and causing it to smoke and melt (unlikely, but hey it's an idea).

Once you notice the smoke, quickly trace the source and turn off the engine. If the bike does not smoke, then potentially the problem is in your headlight wiring as that's high current (and only connected when the front fairing is on).

It will probably be a corroded connector which is such high resistance that it's getting very hot and causing the blue smoke to escape (you know that the job of insulation is to keep the blue smoke trapped inside, right?).

Kaldek

P.S. The "blue smoke escaping" thing is an electrical joke.

[Corbeau]

Eureka!

After removing plenty of plastic (left fairing, dash bezel, etc) my next step was to remove the upper cowl -- and when everything is unbolted, the Service Manual calls for unplugging the four headlight connectors: one of them is melted -- I'll post a pic soon.

The culprit is the LH, low-beam connector. In the 60 seconds times 2 that it was on (and hot) it left two small burn marks in the "dust cover", the rubber boot that's behind the reflectors. Other wires up front/other connectors show no sign of damage/burn/frying.

Thanks LDSRIDER, for your how to on upper cowl replacement. It helped as much as the service manual!

Obviously, I'll get (and install) a new connector. But that doesn't really solve the problem, as the real root cause is not identified.

Thanks for your help.

[Guest kerplode]

Eureka!

Obviously, I'll get (and install) a new connector. But that doesn't really solve the problem, as the real root cause is not identified.

<{POST_SNAPBACK}>

The root cause is that one of those contacts corroded. The corrosion increased the contact resistance across the connection. The increased contact resistance caused an abnormally large amount of power to be dissipated at the contact (P=I^2*R). The large power dissipation heated the connection, melting the plastic housing.

When you put it back together, be sure to coat the contacts with dielectric grease. Also, now would be a good time to clean and inspect the rest of the electrical connections on the bike. Yeah, I know...This is tedious, but it may save you from doing this all over again in a few months or a year.

[Corbeau]

The root cause is that one of those contacts corroded.  The corrosion increased the contact resistance across the connection.  The increased contact resistance caused an abnormally large amount of power to be dissipated at the contact (P=I^2*R).  The large power dissipation heated the connection, melting the plastic housing.

When you put it back together, be sure to coat the contacts with dielectric grease.  Also, now would be a good time to clean and inspect the rest of the electrical connections on the bike.  Yeah, I know...This is tedious, but it may save you from doing this all over again in a few months or a year.

<{POST_SNAPBACK}>

Thanks, kerplode, for the explanation!