Blowing main fuse - need some additional input

[maddad]

Hey everyone, been a long time since I posted here.  I'm having a repeat problem with blowing the main 50 Amp fuse on my 05 FJR ABS.  The bike has just over 200,000 km on it and is ridden fairly hard, tend to get the front wheel in the air once a day. Yes I know that's bad.  Also have pulled the engine myself and replaced a couple of gears and shift forks a few years ago.  And background is an electrical engineer, so have done the obvious.  Hears the sequence of events however.   I live on the East Coast of Canada.  FJR is stored inside family room all winter.  I do have the service manual.

- 3 years ago, headed from Saint John to the Dragon, after doing a wheelie on George Washington Bridge (got to do that once in your life) going through a New Jersey toll somewhere bike just died.  Was very luck that their was no traffic and about a 20 ft wide place to pull over.  Tear down on the highway, found the main fuse, buddy picked one up from Napa, replaced, continued the trip without any problem.  And many more rides after that.

- 2 years ago - riding around NB, after about 200 miles, riding on the flat, not breaking, not increasing or decreasing speed, bike dies.  Replace the fuse, it blows right away. Went through 3 fuses.  Had to truck it home.  Never got back to it for a few days, replaced the fuse.  Bike ran without any problems.  I did search as much as a I could for any kind of short.  Nothing to be found.   Only had to eletrical farkels, Heated Grips and USB charger, disconnected both and they are still disconnected.  I do have LED headlights but I added those after the first time blowing the fuse and they are not blowing the headlight fuse.  No other fuses have blown except for one years ago that was an obvious short.

- 1 year ago -Rode from Saint John to CT.  Coming back through upper NH, midnight, pitch black on an interstate, bike dies again.  Replace the main fuse, bike starts, runs 100ft dies.  Repeat, 100 ft dies.  Have to get it trailered to the hotel.  Lucky our destination was only 12 miles from where I broke down after riding about 350 miles.  Next morning, got more fuses, replaced, rode around the parking lot, blew 3 fuses.  Had a fair bit of the plastics stripped down.  Ended up uhaul to Bangor, storage container in bangor, rental car home, truck back to bangot and pick up bike.  Back home, tried new fuse, blew.  Stripped down a little more, blew.  That was around the 1st of August, went sailing, too frustrated to look at it again that season.

- Over the winter dug back into it.  Over course no short at this point, so no possibility of finding anything.  Checked stator and regulator.  Figured regulator could be a more complex fault so replaced it.  Wiggled every damn wire I could get my hands on under the front plastics and under the tank that I could find.  Could not cause a short.

- 3 weeks ago, keeping much of the plastics off, rode approx. 4 miles.  Main fuse blew.  With bike off, regulator unplugged, all other fuses pulled from the left had fuse panel, new fuses blew.  Trucked it home.  Got out the meter, clear short between one side of the main fuse terminals and ground.  Felt good that there was a confirmed short and I could start debugging.  All other fuses in the panel were out, only fuses still in were the ABS motor fuse and ignition fuses which come off before the main fuse anyway.  Figured the only remaining thing was the ignition switch.

Removed TBar under the tank, rubber protector, reviewed wires again, could see nothing.  Still a short as I monitor that the whole time.  Disconnected what i thought was one of the 2 connectors to the ignition switch.  No more short.  However it was actually the front ABS sensor that I disconnected.  Plugged back in, connected all fuses, started bike.  Rode it up and down the street probably 10 times.  Everything seemed fine.

Tired of buying fuses, picked up a manual reset auto circuit breaker.  (25 Amp).  Connected temporary so I could debug on side of the road if I needed to.

- Last Sunday, rode the same 4 miles as the previous weekend.  Rode slow and steady.  Circuit Breaker trips.  Pull over, pushed in circuit breaker, bike starts, continued on for about 50 miles until I was back home without further incident.

My glove compartment is a little screwed, I setup the cover to stay on with magnets and do not keep anything in there so I am actually sliding the main fuse panel into it and rewiring the main fuse leads and ABS motor leads so that I have the resetable breakers and fuses all inside the glove compartment.  They should do this in production.  Never understood how I could change a tire on the side of the road faster then I could replace a 5 amp fuse.

So looking for thoughts.  Sorry for the long description but looking for more then 'must be a short'.  My next thoughts are:

1) I do need to look at the fuses now after the breaker tripped.  It could be that because the breaker is a manual thing, another fuse also blew.  But everything worked fine so I don't think that is an issue.

2) Some concern over the ABS.  The rear ABS does need service.  I'm going to do that this weekend probably.  I've never really given a good flush to the ABS valves with the maintenance jumper.  While testing, I jamb the rear break enough times to get the ABS to kick in and no fuse blew.  But the ABS does not kick in as quick or consistently did, so I'm guessing it may be sticking and I'm wondering if that could cause a short.  I might expect it to blow the ABS motor fuse before the main fuse.  And when it has blown during rides, I wasn't even using the brake.  So the only way this seems possible is if the ABS system occasionally cycles something.

Not sure besides this.  Any ideas?

 

[infrared]

Maddad,

You can get a clip-on ammeter, to learn which wire is carrying the short.  You do not disconnect any wiring, just clip the single ammeter test-lead to one wire at a time.  When the sometimes short is actively being a short, attach a DC power supply where the battery should be.  They make current-limiting power supplies, so you can apply DC power carefully, and not burn up any wires.  DC clip-on ammeters can read milliamps of DC, these days.  I have used these things; they sure makes testing easy.  I wish I owned such test equipment.

For a quick-and-dirty fix, just get a good front ABS sensor, the gadget-with-wiring that is powered by the connector that you unplugged to kill the short.  You may find one for cheap on eBay, or bite the bullet and just buy it new.  Install and try this new gadget, and see if the short returns.  If that fixes the problem, fine.  It's probably a fool's errand to figure out why the bad ABS sensor went bad, because it is unlikely that you would find what you need to fix it, short of another salvage-yard raid.

You may find a worn spot in the wiring that causes the short, and that could be repaired with some brush-on wire insulation, and maybe spiral-wrap protective sheathing, if you can find the high-temp variety.

You'd have to say more, before I can add anything more here.

Happy hunting.
.

 

[Tlat61]

I had the same problem and it drove me nuts turned out to be the starter Switch would stick and blow the fuse. 

 

[Canadian FJR]

Have you ever replaced or repaired your ignition switch?

Canadian FJR

 

[pierreroyoldtimer]

I had the same problem many years ago on a FJ 1200. The problem was the alternator rotor worn out bearings That allowed side play off the rotor and once and a while, normally on deceleration in my case, The rotor would move sideway a shorted, making the main fuse blowing off. I don’t know if the design of the alternator on the FJR could allow the same behavior on a high milage bike like yours. 
By the way , I also own a 2005, non abs, with 175,000 km. Never had any single mechanical issue with it except fork seals and rear shock. Must say I am a very ‘’ mild’’ rider...