Alternator Whoas...

[Milo_357]

Ok, I know I blew it, don't yell at me....

Left the running lights on...  Drained battery... no luck push starting it...

In the past I had success jump starting off a non-running car battery...

so.... I tried off a classmates truck...

but this time something smoked...  

Battery was off a diesel truck.

Short time later tried off a normal sized car battery.  Fired right up. Yeah!  Pulled jumper of battery, bike died immediately.  Same thing on second try.

 

Two additional things.  When I turn the key on I get the Oil and Neutral lights ONLY.  Generator light is OUT.

When the key is in the OFF position, the generator light glows faintly.

I have pulled the coil out from the LS just in case...

HELPHELPHELPHELPHELP!!!!!

Thanks gang.

Dell in Gatlinburg

[tvrla]

It's quite possible the battery will charge back up. But with the charge light glowing with ignition switch off I'd guess a diode blew.

Charge the battery, replace the diode board with your spare and let us know what happens.

I had something similar happen a couple weeks ago. The bike died when I came to a stop, or maybe I hit the kill switch and somehow failed to turn the key off. Several hours later the bike wouldn't start.

Jumpstarted it and rode off 30miles to the next stop. A half hour later jumped on the bike (started fine) and made it 14 of the 20 miles home when it suddenly died. Jackie brought me a spare battery and rode it home (thank goodness for cell phones!). It wasn't charging. Turned out the rotor slip rings were coated black with carbon that wouldn't conduct - cleaned it off and all has been fine since. My thought is that a bit of contaminants combined with brushes carbon turns into something non conductive - and the system was charging so hard to replenish the battery that the brushes were really working hard, and left so much residue they eventually lost contact.

Many years ago I had a bike I was resurrecting and had charging problems with it. Turned out the brushes were old and not working well anymore. They were probably 30 years old, and I guess brushes age and stop working well, though I don't know why.

[Milo_357]

The diode board is above the alternator at the front of the motor, correct?

Thanks,

Dell

[nhmaf]

Yes, - you will see wires connecting to it from the alternator.   The front side of the diode board is usually painted with a black, or gray coating - if it is still the stock, factory unit.

It does sound like one or more diodes in the diode board are shorted.

Was that diesel truck actually wired for 24V (2 12V batteries in series)??

[montmil]

I still have my burned up diode board from an almost exact same brain fart.

It is the diode board.

Be sure and disconnect the negative battery cable prior to opening up the front case and removing da dead diode dealy. You'll see the toasted parts.

[Milo_357]

Thanks Monte, that does make me feel a bit better to know I am not the only one to do this.

Now it get a diode board.

[montmil]

Spot the toasty areas? I smelled the scorched bit almost immediately as the scent of dumb-ass wafted out of the front cover's vents.




Easy to spot the diode board location above the alternator.



Milo, Do you perchance own an Airhead shop manual?

[Milo_357]

HEY! I know that smell,  I think I've got it bottled...

Yeah, I have a manual (3, actually), but I'm a terrible reader; plus I don't get to interact with my online friends if I go look it up!

 

[Milo_357]

BTW, shouldn't there be a way to put a fuse in the system somehow so that the diode board won't get fried like that???

Anybody?

[Rob Valdez 79 R65]

Well, $30 seems to be a common asking amount on both IBMWR and eBay.

I have a good one from my part-out bike.

$30 +shipping.

PM me.  I can put it in one bubble-wrap envelope inside another.  Should protect it and be cheaper than a box.

[nhmaf]

You don't want a fuse in there.   It would generally cause more problems than it solved.   Better to just avoid doing truly silly things!

[Bob_Roller]

Look at it this way, would you open up the alternator on one of your 4 wheeled vehicles with all of the wires still attached ?

I'm thinking probably not .

Here's something that almost got me a few years ago, I removed the positive lead from the battery and pulled it to the side .

After about 30 minutes or so, I noticed the cable had moved back, and was touching the positive post of the battery .

After 30 years, the cable had taken a shape and when removed, sprung back into its original position .

Now, I use a plastic cable tie to secure the cables when they are disconnected .

If the bike is going to be 'down' for sometime, I remove the battery and put it on the workbench with the battery maintainer connected to it .

[montmil]

And even the Snowbum said don't do it!

[wirewrkr]

If you need to remove the negative cable before removing the front cover, FOR YOUR OWN GOOD, remove it at the battery, not at the speedo cable tie down. There are several reasons for this. I cannot say how many trannies I've seen with screwed up threads there because of this.
More importantly, If you have an accessory socket kit on the bike, when you remove the cable from the transmission, you are still grounding through the socket.
DAMHIK.

[Ed Miller]

Look at it this way, would you open up the alternator on one of your 4 wheeled vehicles with all of the wires still attached ?

Not any more.