[Klutch]

So I have a 98 Honda Shadow 1100. I've had the bike for about a month now, but I know it sat under a tarp for about a year without being touched.(not good, I know) The bike ran great before it was parked, and the bike ran great after it was parked with the exception of the battery wearing dead. Not my 1st bike, and I have outstandingly bad luck, so I knew most likely my stator and V.R. has went bad. I was being cheap/hopeful that it was only the VR. So I ordered a new one, basic install, try to start the bike and I see smoke coming from under the tank. I of course figure my bike is about to catch fire, and that's bad cause my main bike is right beside it. I pull the tank off and see what I thought was a small relay that has lost a gun fight. Had a hole blew in the side if it.
The lovely parts man was more than happy to inform me that wasn't a relay but a silicone rectifier. So 30 bucks later, I'm at home, plugged up the "silicone rectifier" and to my disappointment, when I hit the start button, my damn turn signals blink. All 4 of them. No attempt to fire off, no click of a bad starter relay, just the lovely turn signals blinking away.
I've checked the wires around where it melted down, and nothing seems to be damaged or out of place, everything is plugged in and as tight a connection as possible.
I'm about to the point of hauling the head ache off to the local scrapyard, so any knowledge would be so welcome and appreciated.

 

["Captain D"]

STRANGE ! !

Yeah, I`d be looking at anything that appears like it got warm...

I'm about to the point of hauling the head ache off to the local scrapyard, so any knowledge would be so welcome and appreciated. UNQUOTE

Just ship it down to me
Naah, just joking...
BUT you CAN bring it over and we`ll see what we can find,'
Dennis

 

[Klutch]

I'm out here in North Carolina, in one of the smallest areas you could think of.

 

[swifty2014]

Show us a picture of that rectifier. The only one I know is the diodes for the safety switches on the starting circuit. Should have no connection to a light circuit unless melted wires.
Are these the wire colors?

 

[Klutch]

Hope that shows it ok

 

[Klutch]

And the wires are 2-green w/ red stripe, 1-light greenish blue w/ red stripe and a solid light blue wire. The 2 green w/ red wires went into the same butt connector. Again, hope that helps

 

[swifty2014]

Here is the start circuit with the diode. But the diode is on the grounding side of the start solenoid and should not have very much current going through it to blow the diodes up.

 

[Klutch]

So what would cause the diode to blow out?

 

["Captain D"]

Being a TV repairman I I can say > Electronics just quit working...
Just like everything else...

Dad told me " I don`t ask Why it broke, I just fix it "

Lets RIDE,
Dennis

Sometimes the reason is obvious, others NOT

 

[Klutch]

If I knew what to fix, I would have already fixed it and not asked for help figuring out how to fix it???? Kind of thought that was obvious. Guess not. Sorry. Any actual advise, again, I will be very grateful

 

["Captain D"]

I understand your frustration...

I have a work bench/lift & meter, I`ll be happy to help you but I cannot see the bike from here...

@Klutch my offer still stands...

Bring it over and we`ll see what we can find,
Dennis

I`m not trying to be a [email protected]+ @$$

 

[Troy Jollimore]

He’s just being anecdotal to try keeping your spirits up. I won’t lie to you, though. You’re going to WISH you’d scrapped it by the time you’re done. Electrical troubleshooting of this type is one of the worst jobs out there…

So anyway, your overload has caused a serious short elsewhere in the wiring system. Probably another diode, but where is anyone’s guess. I would start troubleshooting the issues separately. Maybe take a quick check if your blinkers work normally with the key on. The start button is supposed to kill the headlight, but again, why the blinkers? So just start troubleshooting the ‘No start’ issue from there, focussing on the wiring and electricals. You’ll come across the blinker connection soon enough.

 

[PhantomRider64]

I agree that electrical issues are the worst sometime, but are also some of the most rewarding repairs and installations.

When I was working on military tracked vehicles several years ago I had one that was not charging. I started diagnosing it, everything was checking good but it would not charge. After five hours, and many times my boss coming by and suggesting to change out this or that part, I got into a very contorted position under the instrument panel to check for the third time that everything was hooked up. That’s when I saw one connector that was connected but not making contact. Pushed the connector in 1/8” and the vehicle started charging.

Moral of the story,,,be thorough when checking items and don’t just throw parts at a problem.

I know that this might not help with your current situation, it’s just an example of what a PITA electrical problems can be.

It seems that something got hot, obviously, but it might have gotten hot in more than one place. Take some time looking over all of the wiring harnesses to see if there is anything amiss. Check the starting system wires, starting at the battery, been the grounds. Then isolate the parts of the system and check that all work as they are supposed to. Then do the same for the turn signals.

Since the two systems only common denominator is the battery that leads me to believe that adjacent wires have gotten hot and are now making contact. In the service manual for my bike they have diagrams that show how the different wiring harnesses are routed on the bike and how they are routed in the different clamps. If you can find the same thing for your bike you may be able to see where harnesses for the two systems are routed together. This may help in finding the problem.

When you find the cause of the problem please post it here.

Good luck.

Eric


Sent from my iPhone using Tapatalk

 

[nyan]

Just a thought. Not sure if motorcycle relays are similar to the automotive ones but maybe one possibility is that the protection circuit (if it has one) may have gone bad in the "starter relay switch" upstream from that diode that was damaged in the pics. Here is a pic of a typical automotive style relay. They generally have this circuit (in red) built into them to prevent a voltage spike (surprisingly quite high in some cases) when the relay is deactivated.

 

["Captain D"]

A 12V relay ain`t gotta clue IF it`s in a car or on a Bike...

It is not car/Bike particular,
Dennis

 

[swifty2014]

I keep thinking about why there must be a heavy current draw to blow the diode. Maybe reverse current from wrong connections? Look at the diagram closely and make sure no wires are connected to the M terminal of the starter solenoid except the heavy cable to the starter Motor.
And on the B side only the battery power cable and the heavy wire from the voltage regulator.

The control side from the start switches through solenoid coil and the diodes and out to ground should only have a couple of amps.
The starter draws 80 amps, so you want nothing connected to it.

Maybe another thing is to add another ground from battery to engine and frame.
More grounds are always better.

 

[nyan]

A 12V relay ain`t gotta clue IF it`s in a car or on a Bike...

LOL!!! Like i said, just a thought. I am in no way a bike tech that's for sure! Had heard about a faulty relay frying some sensitive components in a car that cost the owner quite a bit of money to figure out so i thought i might throw it out there...

I keep thinking about why there must be a heavy current draw to blow the diode. Maybe reverse current from wrong connections?

Yes, that kind of damage in the pic most likely would have required lots of amps. Reversed connections would do it however, If connections were not reversed then what could cause the above? And why do the turn signals blink the way that they do? Gotta assume that it had a charging system issue to begin with as well

Definitely interested in whats wrong with this one. Hopefully klutch will post findings and a fix....

 

[Troy Jollimore]

Well, a relay is just a ‘remote switch’. Two small electrical wires flip the internal switch between two much bigger ones. If something really goes wrong and the power from the one big wire bleeds to the small one, that could cause an issue in that circuit…

Electrics are really funny things! 😄

 

["Captain D"]

Relays WILL give trouble/ just like anything else electronic...
SOME Last the entire life of the equipment, some go bad BEFORE you sell a New item...
We`ve had TVs right outta the box NOT Work...

Unless the customer request we unbox it in the home we tried it at the shop FIRST...
New "out the Door" customer pick up, We Tried it FIRST...

Yes, Voltage Spikes and reverse polarity CAN & WILL Damage components,
Dennis

I hope I ain`t pissed @Klutch off,
Dennis

((no reply since post #10))

 

[nyan]

Yeah....hope that Klutch comes back with some good news and the ol' Honda is back on the road again.

Thinking that the theory on the "faulty" relay had something to do with a voltage spike that happened when the relay was shut off and the built-in protection.....(spark-preventer circuit lol!?!?)..... was fubar? Maybe similar to the way a spark in an ignition coil is made, except possibly the windings of the electro-magnet in the relay were acting like an ignition coil instead? Tried searchin the web a little for an explanation with not much success other than sparks generated in that fashion don't pack a lot of amps...mostly volts if i read it right. Hopefully Klutch has more success....

Yeah man, sumpthin bigger than a little spark fried that diode set for sure....I sure hope i never have to deal with a problem like that.

Keep us posted Klutch!