ktom300 Posted December 14, 2008 Share Posted December 14, 2008 So I have the wiring diagram from the manual and I blew it up on the copier. Hooked up almost all the wires (one has no home) and I noticed not all the colors match. In the end I have lights but everything appears to be running on AC so the headlight dims when blinkers are turned on or brake light is hit. Also, when you rev the bike up, the bulbs blow. My diagram does not show a regulator, only a rectifier so I'm stumped. Also battery is a loss (original from 1977) but this shouldn't matter right? One last symptom is the blinkers don't flash. Could this be because the flasher is hooked to AC also? Thanks, Tom Link to comment Share on other sites More sharing options...
Moderator Airhead Posted December 14, 2008 Moderator Share Posted December 14, 2008 So I have the wiring diagram from the manual and I blew it up on the copier. Hooked up almost all the wires (one has no home) and I noticed not all the colors match. In the end I have lights but everything appears to be running on AC so the headlight dims when blinkers are turned on or brake light is hit. Also, when you rev the bike up, the bulbs blow. My diagram does not show a regulator, only a rectifier so I'm stumped. Also battery is a loss (original from 1977) but this shouldn't matter right? One last symptom is the blinkers don't flash. Could this be because the flasher is hooked to AC also? Thanks, Tom Hello againn Tom, Its normal for your headlight to go dim when idling because its AC straight from the magneto. however the indicators, rear lights headlamp pilot lamp and instrument lamps are all off battery so they should work from the moment the key is switched on without the engine running. The reason the headlight dims when the indicators or brake light are activated is because there is no reserve of power for them out of the battery. I think the fact that the battery is trashed may have a great deal to do with the bulb blowing issues, the battery itself acts as a form of regulator as the voltage rises then more current will pass through the battery so in a way the battery is a load on the cct, but an open circuit or trashed battery is no load at all and so the voltage can rise to whatever the magneto is putting out at any given speed. the way to prove this theory is. disconnect the battery and measure between battery positive lead to chassis or battery negative lead, run the bike, hold at 5000rpm and note DC voltage. Then fit a good new battery and do the same measurement across battery terminals, hopefully you will see a reduced voltage this time. Link to comment Share on other sites More sharing options...
ktom300 Posted December 16, 2008 Author Share Posted December 16, 2008 The battery thing makes sense so I ordered a new one. Can't hurt. One more question, if the headlight runs on AC then why did it blow out as well? Could the whole system be on DC and sufering from a faulty battery that's not regulating the voltage down? Thanks again Tom Link to comment Share on other sites More sharing options...
Moderator Airhead Posted December 16, 2008 Moderator Share Posted December 16, 2008 The battery thing makes sense so I ordered a new one. Can't hurt. One more question, if the headlight runs on AC then why did it blow out as well? Could the whole system be on DC and sufering from a faulty battery that's not regulating the voltage down? Thanks again Tom Not sure is is AC now without studying a diagram, mine is: thats why i said that! The way to find out is either work it out from the diagram, or fit the new battery turn on the key and dont start the engine, if the headlight works now its DC...if you need to start the engine its AC Link to comment Share on other sites More sharing options...
dan holloway Posted December 16, 2008 Share Posted December 16, 2008 this headlamp usually is affected by other lights when the battery is low. the bulb will keep blow as it sounds like you need a new rectifier that is what is usually the problem in that case. if you want to test it start the bike put a multimeter across the battery and set it to 20v and pick up the revs it should be about 14 if it is below the rectifier needs replacing. if it is above 16 it needs replacing and the battery needs replacing. by the sound of how old the battery is i'm surprised the battery is still going it would't hurt to get a new one anyway. hope this helps Link to comment Share on other sites More sharing options...
Moderator Airhead Posted December 16, 2008 Moderator Share Posted December 16, 2008 this headlamp usually is affected by other lights when the battery is low. the bulb will keep blow as it sounds like you need a new rectifier that is what is usually the problem in that case. if you want to test it start the bike put a multimeter across the battery and set it to 20v and pick up the revs it should be about 14 if it is below the rectifier needs replacing. if it is above 16 it needs replacing and the battery needs replacing. by the sound of how old the battery is i'm surprised the battery is still going it would't hurt to get a new one anyway. hope this helps Dan, weve got history with this problem, i think you mean regulater when you say rectifier dont you?, unfortunately this bike doesnt have one fitted, even as built!! Link to comment Share on other sites More sharing options...
dan holloway Posted December 16, 2008 Share Posted December 16, 2008 we do have history here. some have the rectifier in together that could be why it doesn't list it and is why someone may say rectifier regulater as some bikes have it in one unit. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted December 16, 2008 Moderator Share Posted December 16, 2008 we do have history here. some have the rectifier in together that could be why it doesn't list it and is why someone may say rectifier regulater as some bikes have it in one unit. Yes thats right, sometimes they are combined; I dont think that is the case here though, the drawing lists and shows the correct symbol for a rectifier, we'll investigate that though, if our rectifier is also a regulater it will have cooling fins as part of its constuction; so ktom..does it have cooling fins? Link to comment Share on other sites More sharing options...
ktom300 Posted December 16, 2008 Author Share Posted December 16, 2008 Diagram has it listed as a rectifier and there's no cooling fins or method to sink heat. I think the battery is key in this circuit as a regulator and without it, the bulbs are subject to the max output of the magneto. Everything worked fine at idle except the flasher relay. Also, I found a 6 volt battery for RC around the house and it's enough to power the DC system with the bike off for trouble shooting. Confirmed the headligt does not power up with DC. Link to comment Share on other sites More sharing options...
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