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Discussion Starter #1
First time on the bike in a couple of weeks, as it's been raining a lot lately... Everything was running fine, but about 30 minutes into the ride, right after I some hard acceleration the speedometer and and tachometer completely cut out. Everything else was fine (including the dashboard indicator lights for the turn signals, etc.), so I rode home.

I had the bike apart to replace one of the well nuts on the air intake about a week before, so I originally assumed that I pulled a wire loose and the acceleration jerked it free entirely, but the real problem is a blown fuse on the right hand side fuse box.

I tried replacing it, but every time I turn the key to the on position, it blows out.

I searched the forum for a few hours last night, and it seems people have a similar problem after improperly connecting the battery and blowing a diode on the left hand side of the bike... My battery did die a few weeks ago, and I had to pop start the bike, but I never disconnected the battery, so I'm not sure if the diode would have blown...

Assuming this diode is the problem, I still can't figure out why I'm blowing the pos. lamp fuse (this is 7.5 fuse, it's the third fuse down from the top of the box)... Most people with the blown diode seem to blow the instrument panel fuse which is a couple up from the bottom of the box.


If anyone has any advise I'd be really grateful. A good friend is picking up is Brutale this Wednesday I really want to have my bike on the road by then.


Thanks,

Wyatt Laikind
 

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Discussion Starter #3
For reference, here is the post by MikeF4UK regarding the diode I was referring to earlier. I just bought a multimeter to check the diode though, and this is not the problem (I AM getting continuity one way and nothing the other)... So I still have no clue what the problem could be. I replaced one of the well nuts on my left hand side air intake about the same time my battery died, maybe I pulled a wire loose by accident during that installation???

Again, any help is most appreciated.





"Try this: this is one I helped Dave Whattam (of Senna in mag with elbow down pic) with, I think you may have or had your battery in backwards, I have also included a PDF of the battery and connections, they are quite easy to get wrong:

Ok, in case anybody finds them self in the same position I did, the latch relay fuse (7.5 Amp) keeps blowing, this normally happens after a new battery of a battery going duff or being connected incorrectly.

The solution is likely to be a diode which is located behind the general relay.

The general relay is located on the gear lever side of the bike, take off the side panel, you will see next to alternator 3 square relays, held in place on a metal bracket (8mm bolt), remove the bracket and take off the left most relay from the bracket (rubber clamp just slips off), pull the relay away from its connector, turn the connector round and you will see a leg of wha looks like a bare wire, this is the diode, it goes between the blue wire and the grey wire, check the diode with a multi-meter on te "ohm" range, you should get continuity one way and nothing the other, (thats connect the positive to the blue and the negative to the grey and then vica-versa), if you get continuity in both directions the diode has popped. You can these from any local electronics shop, these diodes cost pence, get two as it always pays to be safe.

Whne you remove the old one make sure you note which direction it was connected, one leg of the diode will be shorter than the other, the new diode will have the legs the same length, match the new one up and then trim one leg to be shorter matching the existing one. Next cut or remove the old diode off, then either crimp the new one in place in the correct direction or solder it (like I did), thats it, but the bike back together.

If you want to check before putting tne new diode in, once you have rrmoved it, turn the igniton one, the fuse should not blow, if it does then you have another fault, but hopefully not.

I hope that the above proves useful to people and save them a huge amount of time and frustarion trying to figure out what has gone wrong

Regards

Dave"
 

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9 times out 10 when you start blowing fuses shortly after working on a bike (especially when none of the work is actually on the electrical system) it's down to damage to the loom when refitting parts.

On the strength of that and from the details you've given I'd initally suspect that you have inadvertantly pinched/pancaked part of the loom when you have put the bike back together.

If you haven't done so already, I'd suggest simply retracing your steps, removing each part you did previously and visually inspecting the wiring loom as you go.

It may be prudent to take a resistance reading of the entire circuit so you have a base reference. It's fairly simple to do that, with the ignition OFF and the blown fuse removed, set your meter for resistance and stick one probe on a good grounding point and the other on the output terminal of the empty fuse holder. To be honest, I can't remember which side is supply and which side is output but as long as you have the ignition off (and you have a stock loom which nobody has pissed around with) you can just probe both, the one which gives you a fairly low reading will be the output side. Take a note of the reading. Keeping the meter connected can also be helpful.

The components powered from that particular fuse are side lights, relay triggers for both hi and lo beam, wheel speed sensor, fuel level sensor/sender and it also supplies the switched live for the dash along with live power for many of the warning/indicator lamps on the dash. So I'd pay particular attention around those parts/areas. While it's not common I have seen people pancake the fuel tank/level sensor part of the loom.

If you have a meter connected to the circuit keep an eye on the readings as you work along the loom, sometimes it can be quite difficult to see the damage so physically moving the loom can sometimes open the short circuit and your meter will show high or open resistance. If your meter has some sort of audible continuity test it's easier to just listen to the meter rather than watching it.

If you've done all that and everything checks out, let me know if you have done any other tests other than what you've mentioned thus far. Trying to track down a short circuit on a bike over the net can be horrendously difficult and on a circuit such as this which powers multiple different circuits/components can be very time consuming so if it's not simple loom damage I hope you have some patience.
 

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Discussion Starter #6
I have taken everything apart and put it back together once already, but I did was looking for more obvious shorts/loose wires. I'll do it again right now with the multimeter attached and see what I can find... If worst comes to worst I can always bring it into the shop, but I'm still having fun with it so I'll keep trying to for now.

Thank you very much for the advice. I have now read a lot of your earlier posts as well now, and they are all very informative.

-Wyatt
 

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If the visual inspection checks out and you're still up for the challenge leave the bike in bits as the next step will be to determine if it's a wiring or component fault (which doesn't take too long).
 

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Discussion Starter #8
I've gone over everything pretty thoroughly now (twice), and still am not seeing anything wrong. I tried adjusting the position of any potentially crimped wires, but still no change in the reading I get out of the empty fuse socket.

Would you mind explaining how I can determine whether it's wiring or a component fault?
 

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What are the resistance readings you are getting for the circuit? That fuse supplies live for a few components that even tho not physically powered up the circuit will still show relatively low resistance. Apologies as I should've noted this earlier.

Those components are the neutral, battery and side stand indicators and if you don't have a physical light switch on your left hand switch gear then the side lights and also the lo beam relay coil will also affect the resistance.

I don't know the exact resistance you will see if the circuit is under normal conditions but based on the assumptions that the warning lights are 1.5Watts and the lo beam relay coil is 100Ohms then...

If the bike is in neutral and the side stand is down and you don't have the ability to turn the lights off from the switchgear the circuit will read approx 9 Ohms.

With the bike in any gear other than neutral and the side stand raised it should read around 11 Ohms.

If you have the option to turn the lights off, then with the bike in neutral and side stand down you should see around 32 Ohms.

And with the side stand raised and the bike in any other gear other than neutral you should see around 96 Ohms.

These are just rough calculations in my head based on some assumptions. If I get some time today, I'll physically test these measurements with my own bike here and update/ammend accordingly.

If you are seeing a reading of less than 9 Ohms then the fault is still there. You also need to account for the internal resistance of the meter itself. Simply touch both probes together, note the resistance reading and subtract that from the readings you've taken from the bike circuits.

If you still have the short, then you'll have to disconnect the individual circuits/components and then recheck the resistance reading, if you are still seeing a short with everything disconnected then it has to be a fault within the wiring loom.

Obviously the tank is already disconnected, but you also need to disconnect the wheel speed sensor (the cable coming from the front sprocket cover), the left hand switchgear and also the dash. Assuming I haven't missed anything, this should basically just leave the wiring for the circuit and nothing else.

If the meter is now reading high or open resistance then the fault is within one (or more) of the components/circuits removed. And if the meter is still reading low resistance the fault is within the loom.

If it's determined that the fault is within one of the circuits/components let me know and I'll do some rough calculations for expected resistance readings for the individual parts.
 

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I've just noticed that the tail light is also powered from that circuit. For the purpose of testing I'd disconnect that completely, not sure exactly what wattage this lamp is but I'd guess it would show as a fairly low resistive load and will make testing for shorts very difficult if it's connected up.
 

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Discussion Starter #11 (Edited)
As of last night, I was getting a resistance reading of 60 ohms out of the top side of the fuse socket, and approximately 0 ohms of resistance out of the bottom side (with all components plugged in).

I have now taken some new resistance readings after unplugging various components, here's what I got:

Unplugging the taillight had no effect

Leaving the taillight unplugged and unplugging the speed sensor also had no effect

However, leaving the previous two components unplugged, and unplugging the dash drastically increased the resistance reading out of the bottom side of the fuse socket (from approximately 0 ohms with the dash plugged in, to 2500 ohms with the dash unplugged).

In all three cases the resistance reading out the top side of the fuse socket was still ~60 ohms.

I'm assuming this means some part of my dash is fried? What do you think?

*edit*
This was all with the sidestand down, and the lowbeam on (I don't believe I have a switch to turn the lights off entirely).
 

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It certainly seems to point to a problem within the dash, although at this point I'd be hesitant to offer a definative answer. I would've expected to see some resistance from the side lights but then, they quite often blow and are very rarely replaced so perhaps they don't actually work.

You could connect everything back up (excluding the dash but) including the fuel tank take another resistance reading and assuming it's not too low, throw a fuse in it and see if it holds.

You can also take some resistance readings across the pins of the connector on the back of the dash. I would have no idea what to expect from these readings but I'd be happy to also take some readings from my own dash for reference and comparison (although not sure I'll have time to do this this evening).

I'd take a resistance reading across pins 9 and 20 of the connector, this is the main switched power feed again no idea at this point what an expected reading would be but I certainly wouldn't expect almost zero.

I'd also take resistance readings across pins 9 and 5 (neutral indicator), pins 9 and 7 (battery indicator), pins 9 and 2 (oil indicator) and pins 9 and 1 (side stand indicator). In all cases and assuming it's a 1.5Watt lamp I'd expect resistance readings in the region of 96 Ohms but that's just a guess on the lamp wattage either way, all the lamps should measure relatively close to each other.
 

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Discussion Starter #13
Alright, I have to run a few errands now, but I will try this tonight and let you know.

I think you are right about the side lights too. Initially, I didn't even know which lights you were referring to and then inspecting my bike, I realized I actually do have side lights, they just don't light up so they must have blown, and then not been replaced by the previous owner.
 

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mmmmmm, I've been following this for a while now, the wire supplies 12v to the dash, in the dash it goes to the main LCD display, bulbs for neutral/oil/batt (gen)/stand and the rev counter supply, I guess if the fuse holds without the dash plugged in your going to have to get the dash looked at, they come apart quite easy so you could always have a look yourself for anything obvious like a displaced bulb etc
There is a link wire inside the dash that stops the bike from running with the dash unplugged, just in case you had a mind too, I think from memory it comes from the kill switch on the RH bar then through the dash itself:)
 

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I checked out my dash earlier today so just for reference, across pins 9 and 20 I see 111 Kohms. It turns out the indicator lamps are actually LEDs so if you don't get a reading when checking the other pins swap your probes round (although it's worth testing in both directions), mine all read more or less the same (open resistance in one direction and in the region of 7 Mohms in the other).

Resistance checking/testing complete electronic circuits isn't the most scientific or indeed conclusive however if your readings are not in a similar region then I'd suspect there is most likely a problem with the dash.

It is worth noting that although things seem to point to a dash problem at the moment, when you disconnect the dash from the loom you also disconnect/isolate a few other circuits from the loom. Anyway, let us know how you go.
 

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I checked out my dash earlier today so just for reference, across pins 9 and 20 I see 111 Kohms. It turns out the indicator lamps are actually LEDs so if you don't get a reading when checking the other pins swap your probes round (although it's worth testing in both directions), mine all read more or less the same (open resistance in one direction and in the region of 7 Mohms in the other).

Resistance checking/testing complete electronic circuits isn't the most scientific or indeed conclusive however if your readings are not in a similar region then I'd suspect there is most likely a problem with the dash.

It is worth noting that although things seem to point to a dash problem at the moment, when you disconnect the dash from the loom you also disconnect/isolate a few other circuits from the loom. Anyway, let us know how you go.

I agree, your talking good real good info here:) but won't most of the circuits he's disconnecting be 'the other' side of a bulb? I wonder if he has a displaced bulb causing the short, (probably the Batt through to the alternator) I can't see the LCD display shorting, but maybe the rev counter?
 

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Indeed, most of the other bits and bobs that disconnect at the same time as removing dash should have no effect. There are things like the temp sensor tho which if it developed a fault could (in theory) end up pulling enough current to cause the main supply fuse to blow, I would expect that these types of auxilary circuits would be current limited within the dash circuitry but without taking a real close look at it you never know.

Curiosity did get the better of me when I pulled my dash and I had a quick look inside. There doesn't appear to be much that could come lose and start wandering around, most of the internal screws look like they'd hit the casings before fully backing out, all the warning indicators are actually LEDs and it's doubtful that both legs of the component would break free. There is one physical lamp to cater for illumination but that has a little socket cap which again I suspect wouldn't be able to go very far before hitting the external casings.

It's difficult to say as you can't really predict how an electronic component will fail but if it's the dash that's causing it to continually blow fuses, there may well be some tell tale signs of pyhsical damage either some browning of the PCB of actual physical damage to one or more electronic components from where they've being drawing excess current.
 

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Discussion Starter #18
Well, you guys will probably be a little disappointed to find out I gave up yesterday afternoon and brought my bike into the dealership to have her looked over. I think I was heading in the right direction (thanks to Hartley Hare and MikeF4UK), but my buddy's going to pick up his new Brutale today, and I wanted to have my bike sorted out in time to go for a ride.

As it turns out, the dash was fine after all. The short was really coming from some melted bits in my license plate eliminator kit. I guess my license plate light is wired in to the same circuitry as the taillight, which is also connected to the same fuse as the dash, gas level sensor, speed sensor, etc.

Apparently the license plate mount/light assembly had been picking up a lot of heat from the exhaust which melted the plastic around the light and shorted some wires.

I think I probably could have tracked this down on my own (with the forum's help), it just would have taken a long time. Even still, I did manage to learn a fair amount about the bike's electronic system, so I'm actually pretty satisfied, even though I had to take her into the shop.

Thanks again to everyone in the forum!
 

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Good to hear you found the problem, also glad you didn't jump the gun and start throwing unnessecary new parts at it (as many people do). Indeed, the license plate lamp is also powered from that fuse, strange that your meter wasn't still reading short when connected to the fuse terminal but hey ho, doesn't really matter now.

I'm sure you would've got there in the end under your own steam but as I mentioned before, fault diagnosis of this type over the internet can be a very difficult and time consuming long drawn out process.
 

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It is always something simple.....Hope the tech's time wasn't too expensive
 
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