Very odd electrical prob - help needed!!
Discussion
My brake lights recently stopped working on my 748 so, upon checking I found both bulbs had gone (got a feeling that 1 had blown a while back). Replaced them and everthing seemed ok untill i noticed my horn not working later that day - checked the fuse and it had blown, it's a shared fuse for both the horn and the brake lights.
This is where it starts to baffle me. I replaced the fuse (7.5A) and checked the lights and the horn - all good. The after I returned from a ride - checked it and the fuse has gone again.
I've replaced the fuse 4 times now and have checked all the wiring for signs of wear, checked the connections and checked the brake light sensors to no avail...
On my last ride I pottled round the town and checked at every set of lights - all ok I thought. Then took it 1 junction along the M25 and stopped and checked - again all fine. So I took it a further 4 junctions and turned round and came home only to discover that it's blown again! ARRRGGGHHHHH
What on earth can it be? Why does it not just blow immediately (assuming somethings faulty)??
Any help/advice would be greatly appreciated.
This is where it starts to baffle me. I replaced the fuse (7.5A) and checked the lights and the horn - all good. The after I returned from a ride - checked it and the fuse has gone again.
I've replaced the fuse 4 times now and have checked all the wiring for signs of wear, checked the connections and checked the brake light sensors to no avail...
On my last ride I pottled round the town and checked at every set of lights - all ok I thought. Then took it 1 junction along the M25 and stopped and checked - again all fine. So I took it a further 4 junctions and turned round and came home only to discover that it's blown again! ARRRGGGHHHHH
What on earth can it be? Why does it not just blow immediately (assuming somethings faulty)??
Any help/advice would be greatly appreciated.
I don't know uch about bike electrics I'm afraid, but I have a go, ignore me if you want, I'll just throw some ideas around.
I'm not sure if the electrical system is 12V or 6V, it probably doesn't make much difference.
Obviously if the fuse keeps blowing, there must be something wrong somewhere. You say that there is nothing wrong with the loom, so I guess you've checked pretty thoroughly.
One thing that might be worth a try is "buzzing out" the offending circuit, not only from fuseboard to endpoints, but each of the end points to the battery terminals. This would obviously test for a broken wire, and a wire shorted to some other circuit.
The other thing to do is temporarily remove the fuse and measure the current through where it would have been. You could do this with brakes on, and the horn working, to get some idea of how close the fuse is to blowing under normal circumstances.
If it's an intermittent fault, it might give you a clue as to the cause of the intermittance. {The secondary cause of intermittent faults is usually vibration. The primary one being some form of short, that is changed as a result of the vibration.}
The other thing to think about is measuring the current with the engine off, and running. I guess that motorbikes have dynamos rather than alternators. If it is an alternator, maybe something is wrong with that, and it's making more volts than it should?
HTH.
Edited to add;
Stuff in brackets.....
>> Edited by dilbert on Saturday 1st October 15:02
I'm not sure if the electrical system is 12V or 6V, it probably doesn't make much difference.
Obviously if the fuse keeps blowing, there must be something wrong somewhere. You say that there is nothing wrong with the loom, so I guess you've checked pretty thoroughly.
One thing that might be worth a try is "buzzing out" the offending circuit, not only from fuseboard to endpoints, but each of the end points to the battery terminals. This would obviously test for a broken wire, and a wire shorted to some other circuit.
The other thing to do is temporarily remove the fuse and measure the current through where it would have been. You could do this with brakes on, and the horn working, to get some idea of how close the fuse is to blowing under normal circumstances.
If it's an intermittent fault, it might give you a clue as to the cause of the intermittance. {The secondary cause of intermittent faults is usually vibration. The primary one being some form of short, that is changed as a result of the vibration.}
The other thing to think about is measuring the current with the engine off, and running. I guess that motorbikes have dynamos rather than alternators. If it is an alternator, maybe something is wrong with that, and it's making more volts than it should?
HTH.
Edited to add;
Stuff in brackets.....
>> Edited by dilbert on Saturday 1st October 15:02
Regulator/rectifier on the fritz?
Check battery connections are tight and check the connections at the regulator/rectifier. I'm guessing a bit, but with the engine running and an avo across the battery the voltage should rise to about 13.5/14 V if it goes much higher then the regulator needs further checking. Better ones are available from https://www.electrosport.com/
Check battery connections are tight and check the connections at the regulator/rectifier. I'm guessing a bit, but with the engine running and an avo across the battery the voltage should rise to about 13.5/14 V if it goes much higher then the regulator needs further checking. Better ones are available from https://www.electrosport.com/
dilbert said:
I don't know uch about bike electrics I'm afraid, but I have a go, ignore me if you want, I'll just throw some ideas around.
I'm not sure if the electrical system is 12V or 6V, it probably doesn't make much difference.
Obviously if the fuse keeps blowing, there must be something wrong somewhere. You say that there is nothing wrong with the loom, so I guess you've checked pretty thoroughly.
One thing that might be worth a try is "buzzing out" the offending circuit, not only from fuseboard to endpoints, but each of the end points to the battery terminals. This would obviously test for a broken wire, and a wire shorted to some other circuit.
The other thing to do is temporarily remove the fuse and measure the current through where it would have been. You could do this with brakes on, and the horn working, to get some idea of how close the fuse is to blowing under normal circumstances.
If it's an intermittent fault, it might give you a clue as to the cause of the intermittance.
The other thing to think about is measuring the current with the engine off, and running. I guess that motorbikes have dynamos rather than alternators. If it is an alternator, maybe something is wrong with that, and it's making more volts than it should?
HTH.
Thanks Dilbert some good ideas there. I also thought that perhaps there was too much power going to the bulbs - the battery reads 12.1V with the engine off and about 13.5V with the engine at about 4k rpm. I think that's fairly normal - would you happen to know?
Good idea about checking the current passing through the fuse normally - if it's close to 7.5A what would you suggest?
I'm going to leave it for today as it looks like it may rain soon and it's not currently garaged..
Any further thoughts appreciated.
Carrera2 said:
I don't know uch about bike electrics I'm afraid, but I have a go, ignore me if you want, I'll just throw some ideas around.
I'm not sure if the electrical system is 12V or 6V, it probably doesn't make much difference.
Obviously if the fuse keeps blowing, there must be something wrong somewhere. You say that there is nothing wrong with the loom, so I guess you've checked pretty thoroughly.
One thing that might be worth a try is "buzzing out" the offending circuit, not only from fuseboard to endpoints, but each of the end points to the battery terminals. This would obviously test for a broken wire, and a wire shorted to some other circuit.
The other thing to do is temporarily remove the fuse and measure the current through where it would have been. You could do this with brakes on, and the horn working, to get some idea of how close the fuse is to blowing under normal circumstances.
If it's an intermittent fault, it might give you a clue as to the cause of the intermittance.
The other thing to think about is measuring the current with the engine off, and running. I guess that motorbikes have dynamos rather than alternators. If it is an alternator, maybe something is wrong with that, and it's making more volts than it should?
HTH.
Thanks Dilbert some good ideas there. I also thought that perhaps there was too much power going to the bulbs - the battery reads 12.1V with the engine off and about 13.5V with the engine at about 4k rpm. I think that's fairly normal - would you happen to know?
Good idea about checking the current passing through the fuse normally - if it's close to 7.5A what would you suggest?
I'm going to leave it for today as it looks like it may rain soon and it's not currently garaged..
Any further thoughts appreciated.
I think Blairout is right. That does sound pretty normal.
If the current is close to the fuse rating, and the voltage on the circuit is as should be, it's time to do some sums. Add up the power rating for all of the end points. I = P/V. If the current exceeds that which you calculate, then something must be leaking out of the loom somewhere.
In respect of the maths I doubt very much that the current would come anywhere near the fuse rating under normal circumstances. The only reason to do it, is that it's not that hard, and you can quickly eliminate a design fault.
If the current isn't nearly at the rating for the fuse, which is quite likely, you can almost certainly eliminate the loom and loads as being part of the problem. (Barring an intermittent loom fault).
If you do have a faulty alternator, it's often the semiconductor regulator that goes, as Mr Blairout says.
The trouble with semiconductors when they fail, is that they are often intermittent, and a whole range of things affect them. Temperature, vibration, magnetisim. This can go on for quite some time untill the device catastropically fails.
If you had an oscilloscope you would see the output buzzing around near 12V, and then every now and then it would jump much higher for a bit.
If I were you, I'd do a final check of the electrics, and measure the current into the offending circuit with the engine off. If it's not excessive assume that the problem is coming from the alternator, and get a new regulator.
If the problem persists after that, start to think about peeling the loom apart.
Sounds like the Rectifier/Regulator (RR), they are a weak point on Ducatis, especially on the earlier models (pre '99 I think) that had the (marginal) single phase 350w alternator - later ones had a 3 phase 520w which is much better.
However before you buy a new one check the connector on the lead between the RR and the alternator, it is a white plug (yellow cables) situated between the V of the engine, behind the battery box - they have a tendency to short through bad contact & heat, the terminals & wires melt giving bad connection problems.
The single phase ones do this more, you can tell which it is by the number of yellow wires in the connector (2 = single phase, 3 = 3phase), if it is bad then changing the whole connector or even soldering the wires together (difficult to quick-release afterwards though) may help. If you can get a more heavy duty connector it is better, as there is a big current through here, especially on single phase models.
I had this problem on mine but luckily I caught it before it did any harm and fitted a new connector - now I check it regularly as due to the heat the connections dry out then the problem gets worse - best to keep it well clean and lubed with vaseline or battery connection grease.
Pic shows a burnt connector on my bike before I changed it, you will need to remove the battery and battery box to get at it, good luck.
>> Edited by catso on Saturday 1st October 16:05
However before you buy a new one check the connector on the lead between the RR and the alternator, it is a white plug (yellow cables) situated between the V of the engine, behind the battery box - they have a tendency to short through bad contact & heat, the terminals & wires melt giving bad connection problems.
The single phase ones do this more, you can tell which it is by the number of yellow wires in the connector (2 = single phase, 3 = 3phase), if it is bad then changing the whole connector or even soldering the wires together (difficult to quick-release afterwards though) may help. If you can get a more heavy duty connector it is better, as there is a big current through here, especially on single phase models.
I had this problem on mine but luckily I caught it before it did any harm and fitted a new connector - now I check it regularly as due to the heat the connections dry out then the problem gets worse - best to keep it well clean and lubed with vaseline or battery connection grease.
Pic shows a burnt connector on my bike before I changed it, you will need to remove the battery and battery box to get at it, good luck.
>> Edited by catso on Saturday 1st October 16:05
Thanks a heap catso! That sounds like it could be it. I haven't done many miles since a track day a month ago and the bike got incredibly hot during that - sounds like it could have caused this.
I'll try and take a look if I get a chance tomorrow and report back.
If not it'll have to be left to next weekend I guess. I have every confidence you're right though!
I'll try and take a look if I get a chance tomorrow and report back.
If not it'll have to be left to next weekend I guess. I have every confidence you're right though!
Right I've taken the battery and box out to get to the yellow wires and it looks like someones beaten me to it - the connectors already been replaced with bullet connectors which look healthy and well connected.
Which I guess just leaves the recifier...
Annoyingly the fuse hasn't blown yet so I'm kidding myself that its all fixed. I'll go for a blat later and see if it blows.
Which I guess just leaves the recifier...
Annoyingly the fuse hasn't blown yet so I'm kidding myself that its all fixed. I'll go for a blat later and see if it blows.
[quote=YamR1,V64motion]
ah Ducati electrics is there anything more annoying?[/quote]
Funnily enough this is the first electrical problem I've had in 2 years and 10k miles. The bike, on the whole, has been good to me although just lately it's been a real bitch. Clutch failing twice - 2nd time in the middle of nowhere in France. Cush drive collapsing leading to the real wheel chewing through the swing arm.
I'm going to change it for either a new Ducati or a Jap bike next year I think.
ah Ducati electrics is there anything more annoying?[/quote]
Funnily enough this is the first electrical problem I've had in 2 years and 10k miles. The bike, on the whole, has been good to me although just lately it's been a real bitch. Clutch failing twice - 2nd time in the middle of nowhere in France. Cush drive collapsing leading to the real wheel chewing through the swing arm.
I'm going to change it for either a new Ducati or a Jap bike next year I think.
Much better than stock Weakest link in the chain... It's not neessarily the RR. You've reminded me of a problem with my old 888 tail light. The bulb housing is made of a fairly malleable plastic and the bulb ends up being a poor fit and keeps blowing. Check the fit of the bulb in the bayonet fitting in good light, it could be that.
RR is giving the right sort of voltage. Only way to spot it in use if it's intermittently failing would be to rig up a semi-permanent volt meter. Check the easy stuff (bulb housing) first
RR is giving the right sort of voltage. Only way to spot it in use if it's intermittently failing would be to rig up a semi-permanent volt meter. Check the easy stuff (bulb housing) first
I've checked the bulbs and they are nicely fitted in the tail - all the connections and wiring look good.
Following Dilberts advice I checked the current across the fuse with the brakes on - 3.05A. I couldn't try it with the horn as I didn't think the neighbours would like it!
I really appreciate the comments/advice here - keep 'em coming!
Anyway of testing the RR if I take it off the bike?
Following Dilberts advice I checked the current across the fuse with the brakes on - 3.05A. I couldn't try it with the horn as I didn't think the neighbours would like it!
I really appreciate the comments/advice here - keep 'em coming!
Anyway of testing the RR if I take it off the bike?
All looks ok - it's actually a newish tail light assembly as I bought a SPS style single seat unit and bought a new tail light assembly rather than transferring the old one.
I'll check the spring at the base of the bulb tomorrow just to be on the safe side but I would have thought that the bulb would simply blow rather than taking a fuse out.
I'll check the spring at the base of the bulb tomorrow just to be on the safe side but I would have thought that the bulb would simply blow rather than taking a fuse out.
Carrera2 said:
[quote=YamR1,V64motion]
ah Ducati electrics is there anything more annoying?
Funnily enough this is the first electrical problem I've had in 2 years and 10k miles. The bike, on the whole, has been good to me although just lately it's been a real bitch. Clutch failing twice - 2nd time in the middle of nowhere in France. Cush drive collapsing leading to the real wheel chewing through the swing arm.
I'm going to change it for either a new Ducati or a Jap bike next year I think.[/quote]
dont get me wrong i do love Ducatis, they are amazing handling and look and sound great but a friend had a 748 and had so many problems with it, it kind of put me off, now hes got a 999 and that seems much better but im still not convinced, i think theyre always going to need a little more TLC, but thinking on it this wouldnt bother me too much as i like to look after my bikes anyway, btw if your looking for a new bike i want to get rid of my 04 plate CBR600RR early next year or possibly even sooner to make way for the 2006 Fireblade im going to replace it with, let me know if you might be interested?, im not going to ride it now until spring.
Don't know why it would only blow certain fuses but the charging system is marginal at best and this is why the RR's fail. One thing to check is your fuel filter - if it's blocked the current draw will increase from the normal 2 amps up to a poss 10A, daft as it sounds a blocked fuel filter is a major cause of RR failure and filters should be changed regularly, has it been done?
Also the RR sits in a very hot place, inside the fairing by the front exhaust downpipe & oil cooler and I know of a few people who have moved them to behind the number plate (need to extend the wires) to keep it cool - a vented V piece also helps although this is not such a big problem in the UK.
Check out this webpage showing just how marginal the charging system is;
www.3dman.com/Tutorials/comments.htm
if you have all the lights etc on there hardly sufficient reserve to charge the battery, it is a good idea to keep the battery on a trickle charger when not in use - this will help extend the battery and RR's life.
Also the RR sits in a very hot place, inside the fairing by the front exhaust downpipe & oil cooler and I know of a few people who have moved them to behind the number plate (need to extend the wires) to keep it cool - a vented V piece also helps although this is not such a big problem in the UK.
Check out this webpage showing just how marginal the charging system is;
www.3dman.com/Tutorials/comments.htm
if you have all the lights etc on there hardly sufficient reserve to charge the battery, it is a good idea to keep the battery on a trickle charger when not in use - this will help extend the battery and RR's life.
[quote=YamR1,V64motion]
dont get me wrong i do love Ducatis, they are amazing handling and look and sound great but a friend had a 748 and had so many problems with it, it kind of put me off, now hes got a 999 and that seems much better but im still not convinced, i think theyre always going to need a little more TLC, but thinking on it this wouldnt bother me too much as i like to look after my bikes anyway, btw if your looking for a new bike i want to get rid of my 04 plate CBR600RR early next year or possibly even sooner to make way for the 2006 Fireblade im going to replace it with, let me know if you might be interested?, im not going to ride it now until spring.[/quote]
Nice bike - I'm going for a litre next time though so thanks but no thanks. I love the Ducati too - great handling and that noise!
dont get me wrong i do love Ducatis, they are amazing handling and look and sound great but a friend had a 748 and had so many problems with it, it kind of put me off, now hes got a 999 and that seems much better but im still not convinced, i think theyre always going to need a little more TLC, but thinking on it this wouldnt bother me too much as i like to look after my bikes anyway, btw if your looking for a new bike i want to get rid of my 04 plate CBR600RR early next year or possibly even sooner to make way for the 2006 Fireblade im going to replace it with, let me know if you might be interested?, im not going to ride it now until spring.[/quote]
Nice bike - I'm going for a litre next time though so thanks but no thanks. I love the Ducati too - great handling and that noise!
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