Yet another LC4 electrical/starting thread

[DolphinJohn]

My 2000 640 E is making the loud buzz from the relay back by the battery, starboard cover.

I rebuilt the starter even though when I opened it up it looked real good. No change. I mistakenly thought it was the starter cable because when I unhooked it from the relay and powered it from jumper cables it would work intermittently.

I replaced the cable and no change. The battery is an Odyssey and has been ruled out (no change when jumping from my truck).

I looked at the relay behind the headlight and tried to do a temporary bypass but I don't think I did it right.
I did notice last night when it was dark out, when I hit the button I can see a spark inside the relay that coincides with the buzz sound from the other relay.

Also, when I hit the button in neutral with no clutch pulled it buzzes and the neutral light strobes but when I pull in the clutch and hit the button the neutral light goes out and the rear relay just clicks once.

Would you say it is probably the front relay? (the small white one behind headlight)

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[mancunian]

sounds like the starter motor or rear relay to me, I would try shorting the terminals on the rear relay if it starts no problem then it rules the motor out, if it does not then try powering the starter motor from another battery say with jump leads taking great care, if it then starts it rules the starter motor out. This would be my initial plan of attack to narrow down possible causes, if it starts when shorting the rear relay that points heavily towards the rear relay, but i would check for voltage on the signal cable before replacing it.

[Mo-Tarded]

Post up the issue here. These guys DO know it all when it comes to the LC-4 platform.

http://advrider.com/forums/showthrea...nduro&page=213

[bmwktmbill]

John,
Do you have the wiring diagram?
Is the ground wire tight at the battery?

Relays are confusing, also the clutch switch and kill buttom and kickstand switch(if present) all add to the problem. I think there should be numbers on the relay terminals so we can figure out how to hot wire it.

bill

[Donkey Hotey]

It's the battery. Odyssey batteries suck ass. Don't care if the jumper cables didn't help. It's the battery. Everything you described, along with the lights dimming, etc. It's the battery.

[warewolf]

Originally Posted by Mo-Tarded

Post up the issue here. These guys DO know it all when it comes to the LC-4 platform.

http://advrider.com/forums/showthrea...nduro&page=213

No, don't. The index is there to collate all these threads, not to be interwoven with the chatter about each issue.

[DolphinJohn]

Originally Posted by mancunian

sounds like the starter motor or rear relay to me, I would try shorting the terminals on the rear relay if it starts no problem then it rules the motor out, if it does not then try powering the starter motor from another battery say with jump leads taking great care, if it then starts it rules the starter motor out. This would be my initial plan of attack to narrow down possible causes, if it starts when shorting the rear relay that points heavily towards the rear relay, but i would check for voltage on the signal cable before replacing it.

Starter motor works fine. When powered from jumper cables directly to the starter it turns fine.

It does not turn when jumping the rear relay, it only sparks. I was doing this by simply shorting between terminals with a pair of needle-nose.

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[DolphinJohn]

Originally Posted by bmwktmbill

John,
Do you have the wiring diagram?
Is the ground wire tight at the battery?

Relays are confusing, also the clutch switch and kill buttom and kickstand switch(if present) all add to the problem. I think there should be numbers on the relay terminals so we can figure out how to hot wire it.

bill

Ground wire is tight, and all other wires seem good. No sidestand on the bike.



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[DolphinJohn]

Originally Posted by Donkey Hotey

It's the battery. Odyssey batteries suck ass. Don't care if the jumper cables didn't help. It's the battery. Everything you described, along with the lights dimming, etc. It's the battery.

You may be right, although the lights don't dim, just the neutral light flickering along with the buzz at the relay. Headlight, blinkers, tail and brake lights are all real strong without the bike running.

We put a meter on the battery and there was no significant drop when hitting the button.

I will swap out the battery from my other bike to make sure.

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[mancunian]

I would also say it is the battery if poor connections are definatley ruled out particularly earth connections.

[DolphinJohn]

Is it normal to see a spark inside the relay? (the small white one behind headlight mask)

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[Donkey Hotey]

Yes, relays and switches make small, visible sparks.

Don't waste another minute of your time until you hook up a known-good battery (that actually starts another bike), and make sure it's properly connected with the screws, not just jumper cables.

I could get into the long-winded discussion of HOW it does this but, everything you've described, I've seen before: normal voltage, no voltage change when you press the button, strong headlight...and it was still the battery.

I'm telling you: Odyssey batteries are lumps of shit. I will never buy another one. You're chasing ghosts. It's 99% the battery. Go read through the Airhead forum and see how many guys do exactly what you're doing because they're so sure it's not the battery. It was the battery.

[DolphinJohn]

It is NOT the battery.

I guess I'm a one percenter.

I swapped the batteries and get the same buzz from the relay, and the Odyssey fires up my F800 no problem.

I also made sure the ground was good and looked for any other problem with wires.

I'm going to order both relays.

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[Donkey Hotey]

Yes indeed, you ARE the 1% but you HAVE to eliminate the battery first.

Next step is to short across the starter relay terminals with a screwdriver. If the engine cranks, it's either the starter relay or something upstream. If not, it's the motor or the cables.

Did you notice any corrosion on either of the cables? What often happens on cars is that acid will get onto the terminals from a leaky battery. The acid will wick down the wires and corrode them down inside the insulation. People clean up the visible part but, corrosion down inside the insulation turns the wire to crap. The same COULD happen on a bike, though batteries rarely last long enough to weep acid.

[DolphinJohn]

Originally Posted by Donkey Hotey

Yes indeed, you ARE the 1% but you HAVE to eliminate the battery first.

Next step is to short across the starter relay terminals with a screwdriver. If the engine cranks, it's either the starter relay or something upstream. If not, it's the motor or the cables.

Did you notice any corrosion on either of the cables? What often happens on cars is that acid will get onto the terminals from a leaky battery. The acid will wick down the wires and corrode them down inside the insulation. People clean up the visible part but, corrosion down inside the insulation turns the wire to crap. The same COULD happen on a bike, though batteries rarely last long enough to weep acid.

I tried shorting across the relay, doesn't work. It just sparks. The starter is good- turns just fine when powered directly from jumper cables.
Positive cable from relay to starter has been replaced. Cables did not have any corrosion at battery.

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