Topic: Total and complete electrical failure, GAAAAAAAA!!!!!

[csendker]

I get a call to pick up my son from school, no problem, the bike's running great, it's sunny and in the mid 60's.  I swing home and pick up his helmet, and take off to his school.  I'm not more than 2 doors away from my driveway (very convienent I might add) and I hear a backfire-type 'pop' and the bike dies.  I'm still rolling, so I try a rolling re-start.  It kinda fires while rolling, but doesn't actually run.  I then realize I've got a total electrical failure.  No juice to the engine, no headlight, no idiot lights, no taillight, no turn signals, nothing, nada, zilch.  I can't really say which came first, the electrical failure or the backfire.  I checked the usual suspects, fuses OK, battery intact, etc. and foud nothing wrong.  No time left, I hop in the truck and head back to work.

Any suggestions as to what may have happened or where to start looking tonight? 

[MRieck]

Battery could have shorted out internally....it has happened to my FJ several times. Battery will read 12.5 volts or so with no load. Turn the ignition on and it drops to almost zero. It will disable everything.

[csendker]

Hmmm, the battery idea's interesting.  I did notice one of the little caps was sheared off.  I can't imagine how that happened, maybe when I put it in and never noticed?  Bottom 1/2 is still screwed in, top 1/2 MIA.  What could cause this besides a crappy battery?  If I find this is the culprit, I don't want a repeate performance.

[petersan]

If you have a volt meter the check that MRieck suggest will take 10 seconds.

Same thing happened to my 550 a few months ago - and as biffta suggests - it was a bad ignition switch.  I pulled it off, removed the rubber backing to the switch, and sure enough one of the soldered wires had come loose.   I re-soldered once and it worked fine.

Happened again (bad solder job) when I was 50 miles from home.  On the road I found a pebble - taped it to the wire with electrical tape and it was enough to get me home. 

Then I bought a new switch on ebay.

[Steve F]

You said you checked the fuses....but did you CHECK the fuses? They may often Look OK but need a continuity check.  Have seen fuses look perfectly fine, but the end cap melted off inside and no current flow.

[csendker]

I didn't spend any real quality time with anything.  Have meter, will test tonight.  And no I didn't check the fuse continuity (good idea!), but everything's out.  With three separate fuses, I would expect something to work as I doubt I would have fried all three simultaneously.  Of course, if I had a mongo power surge...

Battery will read 12.5 volts or so with no load. Turn the ignition on and it drops to almost zero.

There was no noticible change anywhere - all dead - before, during and after I played with the switch.  I do have LED idiot lights that take virtually no power, would they light at all (with a blown battery) when playing with the switch (they didn't)?  And as I think back, I didn't try the park position on the ignition, I wonder if that would work with a blown switch? I guess it would depend on which wire failed on the switch.

[csendker]

And the answer is....the fuses, I think.  Which brings up more questions.  I checked the battery, 12+V before & after throwing the switch, OK.  I checked the ignition switch, everything's still connected, OK.  I pulled each fuse (regular auto fuses, too long) one-by-one and got continuity, OK.  Hold it, the 15A had continuity, but was rusty on one end.  Then I noticed that the fuses seemed to be in the wrong order.

Question:  I thought it was; from left to right, 5A Taillight (Left), 15A Main (Middle), 7A Headlight (Right)?

At least that's what my wiring schematic seems to imply.  The fuse box cover was gone before I bought the bike, and there's no markings on the fuse block.  Mine had it 5, 7, 15; so I swapped the 7 & 15. Suddenly, I noticed it was back alive.  I poped on my helmet & gloves and was about to take it for a run around the block when 'poof' dead again.  The 7 was blown, so I figured I screwed up. I replaced each fuse with a new one, and in the original order 5, 7 & 15.  Vrooom, back in action. 

I swung by the Auto parts store and got the proper 1" long fuses.  I had on the To-Do list to clean the terminals and replace the fuses (I knew they were too long), but I couldn't get the side cover off when it was cold.  Big mistake, going to do this tonight. But what is the proper order?  I'm going to try to decipher by looking at the wire colors, if I can see them all.

Update: there are markings on the block, previously obscured by some gook.  All cleaned up, new fuses, right locations, back up and running.  Thanks all.

[cben750f0]

M8 check your fuse holder... mine was slightly corroded, and it got that hot it melted the soldering and the holder, but the fuse was ok...just  a thought

[KB02]

But here's the real question:

Did you ever manage to pick up your son? You never mentioned that part of it...   

[csendker]

Oh #$%*, I knew I was forgetting something...

[KB02]

 

[cben750f0]

LOL.....  .. thats pretty good...peace