MRBLUESKY Posted April 4, 2009 Share Posted April 4, 2009 Does anyone know where the KMX125 is earthed? I discovered my earth wire on the battery terminal burnt through so i need to check the bike is still earthed. Quote Link to comment Share on other sites More sharing options...
Guest Posted April 4, 2009 Share Posted April 4, 2009 if the battery earth wire is burnt through then the bike is only earthed through the chassis ..you need to rectify the broken battery earth as failure to do this will damage the electronics such as the regulator/rectifier and possible charging components and cdi unit if fitted..... most bikes earth through several cables connecting to the main earth cable ----- to chassis ---- to engine ( sometimes this earths through the mounting bolts ..) also you need to find the cause of the burn through ......... to burn through a wire of the general guage of earthing wire requires a large short circuit ....... Quote Link to comment Share on other sites More sharing options...
MRBLUESKY Posted April 4, 2009 Author Share Posted April 4, 2009 Can you tell me what i should do ? when you say only earthed through the chassis , where else is it earthed from? im new to bikes and know only what ive picked up from this sitethanks Quote Link to comment Share on other sites More sharing options...
Guest Posted April 4, 2009 Share Posted April 4, 2009 basically the chassis is used instead of wires ....so the frame is one big piece of wire ...so if the wire to the battery negative terminal is broken then the electrical system uses the alternative paths available to it ( the frame) but without the ability to connect to the battery as the main earth cable is the only path to the battery you don't say if the bike starts etc ... as if the cable was broken then the electric start would not work etc ... the only way it would possibly start is if it was bump started or has a kickstart and then it would use the engines electrical output to run on but as mentioned the components fitted are designed to work with a battery attached .basically you will need to replace the cable ... what made you look at the cable etc ... any reasons Quote Link to comment Share on other sites More sharing options...
MRBLUESKY Posted April 4, 2009 Author Share Posted April 4, 2009 Great Thanks thats not too much a problem thenits a kmx 125 kickstarti was riding along and notice the temp gauge go off, when i got home the electrics had gone completely. then then came back on ? the previous day the bike fell over, so i thought i best check the battery, i then discovered the negative wire had melted all the plastic cover exposing all the wire, i assumed the battery acid had done this, but i dont think it was this at all .Im not sure what caused this?but if its just a change of wire then , i recon i can manage thatthanks againand any other advise is much appreciated Quote Link to comment Share on other sites More sharing options...
Guest Posted April 4, 2009 Share Posted April 4, 2009 ah right we get to the crux of it is the battery secure in its location ?it may be possible that when the bike fell over the battery earthed out if not secure causing the wires to heat up and melt the insulation .seeing that you lost all electrics means that you will need to investigate the cause of this ..as a test using a jump lead or similar ... connect one end to the negative terminal of battery and then the other to a good metal point on the engine ( bolt etc ) and then check the electrics to see if they work ... if they do you need to trave the earth wire to see if there is any point where it is broken/melted ( this may be hidden under the tank etc etc ) so it may be easier if you are unsure or not very mechanical profficent to seek the assistance of a bike mechanic/electrician Quote Link to comment Share on other sites More sharing options...
MRBLUESKY Posted April 5, 2009 Author Share Posted April 5, 2009 Okthe battery was secure when i opened up the panel, i have the battery in trickler at the mo, so u want me to hook up the battery positive and then hook the neg to a metal point. if i get power then thats bad news? is that right? so if the lights dont come on then does that mean there is no brake in the earth connection?thanks so much for this help Quote Link to comment Share on other sites More sharing options...
Guest Posted April 5, 2009 Share Posted April 5, 2009 thats it if as you say you lost all power (electric wise) connect the positive connection of battery then apply a jump lead to negative terminal to a good engine bolt ( if possible exhaust manifold bolt ( where the exhaist joins teh engine)... and see if you get power .... if not try attaching to the frame at a good earthing point ( again something like an engine to frame mounting bolt if possible ( nothing stainless/chrome/heavily painted ) and again see if you have power .....if power is there then ..... remove jump lead and connect the bikes earth wire to the negative and see if you have power if not then there is a problem in the earth/negative cable that needs to be traced .....you will need to trace the cause of the reason why the wire has burnt do not just renew the cable and think oh well you run the riskof a fire in the worst case scenario ...reason i ask if the battery moves is that if it was a specific circuit related problem it would blow that fuse ...can you post a pic of the cable if possible Quote Link to comment Share on other sites More sharing options...
MRBLUESKY Posted April 5, 2009 Author Share Posted April 5, 2009 Hiit i have electric power when i tested it via the jump to the frame, and i have just replaced the wire. .and all is working okanything else i should check for?thanks Quote Link to comment Share on other sites More sharing options...
Guest Posted April 5, 2009 Share Posted April 5, 2009 Hiit i have electric power when i tested it via the jump to the frame, and i have just replaced the wire. .and all is working okanything else i should check for?thanksas mentioned before, find the fault, otherwise the wire could burn out again, with disaterous results, bike fire Quote Link to comment Share on other sites More sharing options...
MRBLUESKY Posted April 5, 2009 Author Share Posted April 5, 2009 How do i know where the fault is , or if there is a fault now? i thought the test with the jump lead identified the bike was earthed? or have i mis-understood .thanks again everone Quote Link to comment Share on other sites More sharing options...
Guest Posted April 5, 2009 Share Posted April 5, 2009 How do i know where the fault is , or if there is a fault now? i thought the test with the jump lead identified the bike was earthed? or have i mis-understood .thanks again everoneyou will need to trace the cause of the reason why the wire has burnt do not just renew the cable and think oh well you run the riskof a fire in the worst case scenario ... as a test using a jump lead or similar ... connect one end to the negative terminal of battery and then the other to a good metal point on the engine ( bolt etc ) and then check the electrics to see if they work ... if they do you need to trave the earth wire to see if there is any point where it is broken/melted ( this may be hidden under the tank etc etc ) so it may be easier if you are unsure or not very mechanical profficent to seek the assistance of a bike mechanic/electriciantake the panels tank off, one by one and check any wiring, if it has shorted on the frame etc, there will be tell tale marks, scorching, exposed wire etc. Quote Link to comment Share on other sites More sharing options...
Guest Posted April 5, 2009 Share Posted April 5, 2009 the using of the jump lead was to diagnose the fact that the earth lead was broken and that is what had caused you to lose power ... you now need to find out what caused the wire to burn through .... this is not a common occurence ... as mentioned for a wire to burn through of that guage ( thickness of wire) requires a heavy load such as if the two terminals of the battery were connected together .... that is why i asked about battery security etc...... Quote Link to comment Share on other sites More sharing options...
MRBLUESKY Posted April 5, 2009 Author Share Posted April 5, 2009 ok thanks whilst connecting the battery back up i pushed it into position and the positive terminal toched the exhaust which is only about 2 mm above it. this had sparks fkying everywhere as you can imagine, i cant believe how close the termininal is to metal. i pushed the ruber cover over it and all is ok . i was wondering if this could of been the cause of the negative wire melting down? as i mentioned earlier in the post ,the bike had a fall the day earlier and this could of pushed the battery against this pipe.what do you recon?cheers guys, its fantastic to have this support Quote Link to comment Share on other sites More sharing options...
Guest Posted April 5, 2009 Share Posted April 5, 2009 ok thanks whilst connecting the battery back up i pushed it into position and the positive terminal toched the exhaust which is only about 2 mm above it. this had sparks fkying everywhere as you can imagine, i cant believe how close the termininal is to metal. i pushed the ruber cover over it and all is ok . i was wondering if this could of been the cause of the negative wire melting down? as i mentioned earlier in the post ,the bike had a fall the day earlier and this could of pushed the battery against this pipe.what do you recon?cheers guys, its fantastic to have this support personally i think we now have the cause of this sorted ......reason being is that the positive cable is thicker than the negative generally so takes longer to heat up.If a direct short is present near the battery it is not fused so no fuse will blow and the wires take all the current and therefore the negative takes the bigger brunt of it all keep an eye on it try and secure the battery better or try to add a bit more insulation in that area but without causing more problems of material on the exhaust and little hint try to give all data available with future problems .....aids diagnosis ... Quote Link to comment Share on other sites More sharing options...
MRBLUESKY Posted April 6, 2009 Author Share Posted April 6, 2009 I will try and follow the earth wire and check for problems, but its difficult with it all being taped up with other wires, whic then go off in different directions, and then it splits into 2 earth wires going all over the place.i will update if i find anythingthanks do much for the help, thats a drink i owe you Quote Link to comment Share on other sites More sharing options...
Guest Posted April 6, 2009 Share Posted April 6, 2009 check to make sure the battery is in the correct way round ..... if the cables seem to long in their present locations ... see if battery will rotate 180 degree's and see if cables fit.....but please check that it will not touch on anything etc before doing this /connecting wires .... Quote Link to comment Share on other sites More sharing options...
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