WR450 Electrical Issue

[Jeffrey SmithMember]

So it seems I left the key on after my last ride and when I went to start it this morning no power. :blush:

No problem I thought, I have jumper leads so hook them up and as soon as I do the starter winds over. :huh:

I pulled the starter button out thinking it was stuck on or had somehow made a permanent connection while it was just sitting in the shed. I cleaned it up and put the multimeter on and it appears to be working normally i.e. no connection when out and connection when pushed.

WTF is going on??????

[Jeffrey SmithMember]

Excuse my ignorance but do bikes have solenoids? Maybe I burnt it out leaving the key on.

[Nick JacksonMember]

Sounds like a strange one mate , only having the key on shouldn’t have engaged a starter solenoid ( if it has one ?) as that’s what the buttons for , if the button is open circuit like you tested.
Have you checked terminals and push connectors to make sure that nothing has melted and shorted out due to bad connection and being on all night ?

[Jeffrey SmithMember]

Nickj wrote:

Sounds like a strange one mate , only having the key on shouldn’t have engaged a starter solenoid ( if it has one ?) as that’s what the buttons for , if the button is open circuit like you tested.
Have you checked terminals and push connectors to make sure that nothing has melted and shorted out due to bad connection and being on all night ?

I haven’t checked the wiring all the way through yet but it looks like I will have to.

By the way, the key has been on for more than a week.

[GregMember]

The button sends a voltage signal (small wire) to a soleniod or relay (depends on who you sepak to) the soleniod has the main power direct from the battery (big wire) to the starter. My money would be on a faulty relay / soleniod if your testing of the switch is correct Or the starter soleniod stuck in

Simple terms

The power from the battery to the starter doesnt go through your button because the size of the button and the wires back and forth would be huge.

Just a thought the starter could be stuck in, didnt you have it apart recently

TB

[katrina ratcliffMember]

Nice diagram and explanation TB…. even I can understand that one…… thanks…

Kat

[Jeffrey SmithMember]

Thanks TB,

yeah I did have it apart. The starter doesn’t have a seperate solenoide/relay like in the diagram though so I will have to pull the whole thing out again by the looks. I was going to have to anyway as I have ordered a new starter but was hoping to only do it once more..

Maybe I should have mentioned too that it won’t start with the kicker either. I disconected the battery and tried kicking it with no joy, not even a cough or fart.

[Adam RodgersMember]

Jeffro

See attached diagrams they will help you fault find.

[attachment=3450]YamahaWrf450WiringDiagram.pdf[/attachment]

[attachment=3451]YamahaWrf450StartingCircuit.pdf[/attachment]

Adam.

[jamieMember]

Good diagams,i would try and get some power straight to the starter motor bypassing the loom to hopefully eliminate it,probably worth an arm and a leg :angry: . Then if the starter turns work back through the cheaper items.

good luck

[Jeffrey SmithMember]

twobanger wrote:

Good diagams,i would try and get some power straight to the starter motor bypassing the loom to hopefully eliminate it,probably worth an arm and a leg :angry: . Then if the starter turns work back through the cheaper items.

good luck

Thanks but the problem is not that the starter wont turn, it’s that it wont STOP turning.

[Nick JacksonMember]

Trailboss wrote:

The button sends a voltage signal (small wire) to a soleniod or relay (depends on who you sepak to) the soleniod has the main power direct from the battery (big wire) to the starter. My money would be on a faulty relay / soleniod if your testing of the switch is correct Or the starter soleniod stuck in

Simple terms

The power from the battery to the starter doesnt go through your button because the size of the button and the wires back and forth would be huge.

Just a thought the starter could be stuck in, didnt you have it apart recently

TB

I can’t see why the starter relay would suddenly latch just because the key was on ?? Surely the button would need to be at fault too for this to happen ?

How many wires are coming out of the starter Jeffro ?

Nick

[jamieMember]

My reading needs to improve :laugh: back on topic,i’d change the relay first.

[RoyMember]

From my days back when I had a wr I seem to remember that 250’s would run without a battery but 450’s wouldn’t for some reason. At the very least the 450 would need the flat battery to still be in the circuit to kick start.

From the wiring diagrams and your testing that shows the switch is still right the problem with the starter motor going non stop has got to be in the starter relay. For some reason it is staying in the on position. Even if there is a short in the starter motor it will not get power unless the starter relay closes to let power through. Don’t ask me where the relay is or what it looks like but if you follow the wire back from the starter motor it should go straight to it. My thoughts anyway.

[RoyMember]

As a ktm owner I have had a bit of experience with starter motors (but not the circuitry). I’m assuming that yamaha are like ktm with one positive wire going to the starter and then earthed through the engine.

The funny thing is I had a yamaha, starter always worked but it used to chew through batteries, now I have a ktm and the battery always works but it chews through starter motors. This is not meant to make you laugh as this is the tech help section.

[Nick JacksonMember]

Don’t right off the starter relay until you have made sure their is no wiring short causing it to latch. This should be as simple as disconnecting the switch wires going to the relay and reconnecting the battery. At least that will eliminate the switch circuit.

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