Bike wont turn over after a rain

[ryanschoebel]

Hey all, so my brother has had the FJ for a few days while his bike is waiting on a new tire. Today, while we here in Phoenix are having a rare rain, he left it out all day, getting poured on. Now, the bike wont turn over. The motor will turn when i hit the start button, but it doesnt sound like the starter is trying to catch. I looked for a short, and the positive battery terminal is shorting against the frame. I figure it will likely be fine once it dries out, but what would cause this, and how can I prevent it from happening again??

[ZOA NOM]

Battery voltage is likely very low, possibly drained. Get that positive post clear of any frame touching.

[Pat Conlon]

Yep

http://www.fjowners.com/index.php?topic=3292.0

[ryanschoebel]

Battery voltage is likely very low, possibly drained. Get that positive post clear of any frame touching.

Sorry, poor wording. The terminal is not actually touching the frame, nor can i see anywhere where the wiring is shorted to the frame. But my ohm meter still says that there is  fault on the positive side, to the frame of the bike.

[Pat Conlon]

....and the fun begins...

[Sparky84]

Maybe this

http://www.fj1200.info/Engine.html

[racerrad8]

Confirm your ground wire is tight at the back of the motor. You probably had it loose when you were working on that oil leak.

Randy - RPM

[TexasDave]

 

[ryanschoebel]

Sparky, that was my thought, that maybe the coils just got wet. Randy, thanks for the tip, I will check it out for sure. Pat, once it dries, I'll chase that short down if it still exists. I'm not looking forward to it. Dave, not sure which part you are referring to haha

[Troyskie]

I've bought nearly every set of FJ coils from wreckers I come across as spares. 1 in 3 won't work wet. 1 in 5 are just old and buggered.

Coils can go off like a prawn in the sun. On day they are fine, but one little teensy bit of rain and they're gone. Warm up, dry off and they work again.

It is great to have working coils as swapperoonies when diagnosing shitty fucking electrical gremlin c*nts.

I've been learning hard these last few years about different FJ systems, electrics for me are still for magicians. (Al, where's your smoke bomb?  ).

Of recent experience of my incompetence I discovered the importance of 'the grey wire circuit'. Mate, obvious things first (and you seem to know what to do with a multimeter), I recently had the grey wire to the tacho intermittently short (my fault) and it dropped a coil. Being wet I'd follow the grey wire after the mains are ruled out, or even just disconnect the instruments plug. That will localise the fault to only half the loom. The bike will start fine with the instruments unplugged.

[TexasDave]

Troyskie has some excellent advice on coils. Most from breakers are bad. There is a reason for this and why they are affected by moisture. The location of the coils on our bikes exposes them to a lot of engine heat. This heat degrades the plastic the coils are embedded in. It also causes the plastic to shrink and then crack. As our bikes age the plastic goes through many heating and cooling cycles and eventually the cracks allow water in which shorts out the coil. Sometimes allowing the coils to dry out will return them to working order. Sometimes exposure to water many times will corrode them and they will not work dry or not. Testing the impedance with a volt/Ohm meter on both the primary and secondary is a good way to see if they work. These values are year specific and are slightly different among years. Swapping coils is also a good way to see if you know you have a good one that works. As time goes on we will all have this problem as age and mileage increase. Thank goodness there are aftermarket coils available.

As Troyskie has said the grey wire that runs from a coil to the tachometer could be shorted which would short the coil too.

Dave

[T Legg]

 On a US 84 fj1100 the wire from the tach is the orange wire and affects coils 1&4

[Troyskie]

Darn US colour changers!

What about coils 2 & 3? 

[ryanschoebel]

Darn US colour changers!

What about coils 2 & 3? 

coils 2 and 3 are the grey wire,and go straight to the ignitor unit, according to the wiring diagram in my Haynes Manual

[T Legg]

I have no idea why the US bikes use the orange wire for the tach and every other bike uses the grey wire .