Fried Wiring When Trying To Start Bike, Need Damage Assessment

[Reid]

To bench test the soleniod you will want to connect one of the B wires to the neg on your battery, then momentarily touch the other wire to the positive. If it doesnt click its no good if it does it could still be bad. Meaning the coil (inside the soleniod) is good but it may not be conducting power between the A posts. This will be easiest to check with the beep setting on your meter (if so equipped), do the same test as above but when you connect the small wire to the battery pos hold the meter leads one on each of the A posts

 

[Reid]

get a beep and its (99%) good, letting you know that power will travel through the soleniod. You can also use this beep setting to check for shorts to ground but we will burn that bridge when we get to it

 

[XSLeo]

On the starter relay, or starter solenoid, you have the two large bolts that the cables attach to, you have two small wires coming out. One is blue/white, one is red/white.
In use power is fed to the red/white wire, the blue/white wires goes to the starter push button where when pushed it grounds the blue/white wire.
This powers the relay to close the contacts between the two large bolts.
Now to test you relay hook your meters leads to the large bolts. Now with some extra wire hook the red/white wire to the positive on a 12 battery, hook another wire to the blue/white wire, touch this wire to the negitive on the battery.
The relay should activate, you will know by the click.
The meter should go from an infinity reading to a low ohm reading when you hear the click.
Now to test the starter you can hook a heavy cable. The ones off the bike will work fine. Hook one cable from battery positive to one of the relays large bolts, the other large bolt run a cable to the starter. Now use jumper cables to hook the negitive on the battery to the starter case. Now with the same hook up used to test the relay touch the blue/white wire to battery negitive.
This should make the relay click and the starter spin.
Leo

 

[YL82]

I would start by looking at the starter soleniod make sure the coil wire is not touching a ground (frame, ground wire, etc.). It most likely will be related to start button wire since thats what you were doing when it happened. If its not grounded then the soleniod could be bad (never heard of one frying a harness) and pulling a high load (amps = heat). I would replace the harness and the soleniod if it were me, also check the handle bar switches for damage.

Update on my progress:

Took at look at Bar Switch at START Button (per your initial suggestion and one I later came across from 5twins) and low & behold its very corroded, so I've ordered a new one from Mikesxs. Had to deal with a "gaggle" of wires behind Headlight, but no big deal to disconnect the 6 wires.

Starter Motor: Very dirty. Armature: Dirty, needs sanding at commutator. Plan to clean starter "innards" with LPS flashless electro contact cleaner.

Armature Brush Set: While I haven't really measured or assessed the brushes, I went ahead and ordered an OEM set.

Question: I assume that new brushes will have to be soldered on. For condutivity reasons or whatever, should a certain type solder and flux core be used? 40/60 Lead/Tin?, Silver?, Rosin Core, Solid Core, etc...??

I've also ordered a new main wiring harness, a new fuse holder along with the new bar switch assembly.

Battery: I've had my battery on a battery minder for a few days. Checked voltage with a multimeter: 13.4 Volts.

Question: Is this voltage measurement OK?

 

[YL82]

On the starter relay, or starter solenoid, you have the two large bolts that the cables attach to, you have two small wires coming out. One is blue/white, one is red/white.
In use power is fed to the red/white wire, the blue/white wires goes to the starter push button where when pushed it grounds the blue/white wire.
This powers the relay to close the contacts between the two large bolts.
Now to test you relay hook your meters leads to the large bolts. Now with some extra wire hook the red/white wire to the positive on a 12 battery, hook another wire to the blue/white wire, touch this wire to the negitive on the battery.
The relay should activate, you will know by the click.
The meter should go from an infinity reading to a low ohm reading when you hear the click.
Now to test the starter you can hook a heavy cable. The ones off the bike will work fine. Hook one cable from battery positive to one of the relays large bolts, the other large bolt run a cable to the starter. Now use jumper cables to hook the negitive on the battery to the starter case. Now with the same hook up used to test the relay touch the blue/white wire to battery negitive.
This should make the relay click and the starter spin.
Leo

Thanks, Leo!

I'll be printing out these instructions to bench test my starter and solenoid...

Terminology: Your post caught my attention, cause I had not thought that a "Starter Relay" is synonymous with "Starter Solenoid". I've also seen this part called a "Starter Switch Assembly" on Ebay.

I just ordered a Starter Relay from Mikesxs for $17 and was damn close to ordering a new OEM Starter Switch Assembly from Ebay (Beach_Yamaha) for $100 and I see its the SAME DAMN PART!

Whew!

You just saved me $100+, Leo!

I verified by checking the OEM# on Ebay part with Mikesxs part and they are same (447-81940-10-00).

 

[YL82]

I don't want to get off point here, but I took some images of some electrical parts.

With respect to my starting issues, not sure if these parts should be on the list of culprits to test, replace, etc.

For each of these parts, what problems would be seen if there were issues with them?

I believe I'm looking at the voltage regulator in one image and the rectifier in other image, but not sure what the gizmo is below and to the right of the rectifier.

Basic stuff that I should already know, my apologies, but one has to start someplace....

Are there any bench tests that can be (or otherwise need to be) run on these parts or are they best evaluated when the bike is running (i.e., on a bike with a non-fried wiring harness!)?

Thanks Mentors!

 

[YL82]

On the starter relay, or starter solenoid, you have the two large bolts that the cables attach to, you have two small wires coming out. One is blue/white, one is red/white.
In use power is fed to the red/white wire, the blue/white wires goes to the starter push button where when pushed it grounds the blue/white wire.
This powers the relay to close the contacts between the two large bolts.
Now to test you relay hook your meters leads to the large bolts. Now with some extra wire hook the red/white wire to the positive on a 12 battery, hook another wire to the blue/white wire, touch this wire to the negitive on the battery.
The relay should activate, you will know by the click.
The meter should go from an infinity reading to a low ohm reading when you hear the click.
Now to test the starter you can hook a heavy cable. The ones off the bike will work fine. Hook one cable from battery positive to one of the relays large bolts, the other large bolt run a cable to the starter. Now use jumper cables to hook the negitive on the battery to the starter case. Now with the same hook up used to test the relay touch the blue/white wire to battery negitive.
This should make the relay click and the starter spin.
Leo

Take a look at my graphics (per your instructions) for testing the:

1) Starter Relay and
2) Starter Motor & Starter Relay

Have I got it right?

I realize that connecting wires don't have to be red and blue....

Thank You!

 

[Reid]

looks right to me, well done

 

[YL82]

Thanks, Reid!

 

[XSLeo]

The pics in post #26, the one with the green wire wound resister is the voltage regulator. It will have a green, a brown and a black wire.
The other pics is a safety relay. It has a black, a yellow, a red/white and a red wire.
On your test circuits, yes, those hook ups will test you starter and starter relay.
Leo

 

[YL82]

Do the Jumper Cables to be used in the testing of the Starter Motor & Starter Solenoid need to be heavy duty automotive grade/gauge or can a ligher gauge set be used?

 

[Reid]

I would use the automotive ones but that is only because I have some and they are ready to use. You can use something smaller try to stay with something close to the size of the battery cables on your bike

 

[XSLeo]

If you have a set use what you have. If you don't have a set then you have been pretty lucky with your batteries.
If you buy a set buy a good set. Not the cheapest you can find.
Leo

 

[YL82]

The pics in post #26, the one with the green wire wound resister is the voltage regulator. It will have a green, a brown and a black wire.
The other pics is a safety relay. It has a black, a yellow, a red/white and a red wire.
On your test circuits, yes, those hook ups will test you starter and starter relay.
Leo

Test Results on Starter Switch (Solenoid):

Solenoid Clicks

Test Results on Starter Switch and Starter Motor:

Solenoid Clicks; Starter Motor: Nothing.

Going to try test again after recharging my battery (to make sure battery wasn't to blame), but does this possibly point to faulty solenoid even though it clicks?

I cleaned commutator (600 sandpaper and hosed down with cleaner) thoroughly. Went ahead and replaced brush set. Replaced oil seal and used white lithium grease. Replaced both large O-rings with new ones (damn hard to find those).

 

[rebel542]

I've seen this happen before on other bikes. You either have a bad ground on the battery negative cable to the frame or an isolated engine. Lots of frame paint will prevent the engine from grounding to frame. When you push the starter button in the starter motor is trying to draw all it's amps through the tiny wires in the harness. If you install a new harness it will burn up too if the problem isn't found and corrected first. Good luck.

 

[YL82]

Your last statement is something that's been in the back of my mind as I order new parts, refurbish the starter, etc. I have yet to autopsy the fried wires , but determining the root cause is a must before I put the new harness at risk.

I understand your comments on the grounding thing, but what is an isolated engine?

Thanks!

 

[rebel542]

What I mean by an isolated engine is cases where the engine is poorly grounded to the frame. This is usually encountered after a newly painted frame. The engine simply doesn't touch the frame because of the heavy paint. The starter motor being attached to the engine cases means it has to find a different route for the cranking amps required. They will run through the ground wire in the harness (black) and burn the wire. I've also seen paint so heavy in the bolt hole for the ground cable, just behind battery box on the frame, that it would ground good enough to run lights and kick start but smoke the harness if you hit the starter. And last is the battery box ground. Never run your ground cable to the battery box. It has rubber dampers on all 4 mounts and will send all starter amps through those tiny wires in the harness and they just won't take the load. I still think you have a ground issue but can't imagine how with what you say you have done service wise. Hope this helps.

 

[rebel542]

One more thing. You can always run a short heavy ground cable from the engine to a good clean ground point on your frame.

 

[Reid]

like to one of the starter bolts (longer bolt if need be)

 

[YL82]

Lots of good information, rebel 542. Thanks!

It could be that you've hit on the real problem, I'll provide updates as I work through this.