Vmax540 Posted March 31, 2010 Share Posted March 31, 2010 ________________________________________ Hello ! We have a silver 1972 Yamaha RT1 360 with a 6 volt system which puts out 11.5 at idle to almost 16 volts when rev'ed. We replaced the 2 wire voltage regulator with 2 other used 6 volt regulators with the same results. You can guess what is does to the rare 6v head light bulbs......I can not think all 3 6 volt regulators are bad but, then if they were good how could we have such high voltage at the H.L. socket ? So, I hook up an old 30 watt 12v bulb and it was real bright for like 30 seconds then poof.... I noticed if you wiggle the ignition/head light switch the head light changes brightness.... certainly, this couldn't be the cause of the high voltage ? Maybe it is as simply as using a 12 volt regulator and head light bulb ? Is the 6 volt battery simply for the ignition system ? Any one know where I could find a wiring diagram ? Thanks for any help ! Link to comment Share on other sites More sharing options...
Moderator Airhead Posted March 31, 2010 Moderator Share Posted March 31, 2010 I didnt think these bikes actually had a regulator...only a rectifier. in fact the regulation is so basic that excess voltage is sunk by the battery, if tou have a bad battery...or disconnect ther battery on these bikes you get the same problem. Cosequently batteries and electrolyte levels need to be well maintained and rectifiers need to be working correctly. Also drawings and circuits were basic for these bikes. http://www.slimduck.com/rt1360_wiring.htm http://www.slimduck.com/rt2360_wiring.htm ...Paul Link to comment Share on other sites More sharing options...
Vmax540 Posted March 31, 2010 Author Share Posted March 31, 2010 Wow, you are right there is no voltage regulator and I see a diode in the epoxy so, it is a rectifier ! Maybe, I will put a 12 volt regulator on the lighting circuit and use a 12v bulb and be done ? Thank you ! Link to comment Share on other sites More sharing options...
Moderator Cynic Posted March 31, 2010 Moderator Share Posted March 31, 2010 Wow, you are right there is no voltage regulator and I see a diode in the epoxy so, it is a rectifier ! Maybe, I will put a 12 volt regulator on the lighting circuit and use a 12v bulb and be done ? Thank you ! From previous posts in the past, there will be a cursory regulator. Basically a resistor in the loom somewhere that controls the peak voltage. Its basic and generally works after a fasion. Trouble being its in the earth/ground circuit which is not normally shown (especially on early drawings for clarity ) just to confuse things. I would advise against using a 12v bulb. In the short term it may work but generating double the voltage and the associated increace in power will stress the other electrics. I'm willing to bet they will be a lot rarer than the bulbs. Not to mention it may be damaging the battery as that could also be coping for double figure voltage. Personally i would be looking at sneaking a more modern proper 6v regulator in somewhere out of the way, although it needs some cooling as it can get warm it should be possible to sneak it in. As to wiring, the lighting circuit/charging circuit feed (i'll double check that later) will need to be connected to it, this then allows excess voltage to bleed off and supposedly keep the headlight at a constant level. Link to comment Share on other sites More sharing options...
Vmax540 Posted March 31, 2010 Author Share Posted March 31, 2010 From previous posts in the past, there will be a . Basically a resistor in the loom somewhere that controls the peak voltage. Its basic and generally works after a fasion. Trouble being its in the earth/ground circuit which is not normally shown (especially on early drawings for clarity ) just to confuse things. I would advise against using a 12v bulb. In the short term it may work but generating double the voltage and the associated increace in power will stress the other electrics. I'm willing to bet they will be a lot rarer than the bulbs. Not to mention it may be damaging the battery as that could also be coping for double figure voltage. Personally i would be looking at sneaking a more modern proper 6v regulator in somewhere out of the way, although it needs some cooling as it can get warm it should be possible to sneak it in. As to wiring, the lighting circuit/charging circuit feed (i'll double check that later) will need to be connected to it, this then allows excess voltage to bleed off and supposedly keep the headlight at a constant level. cursory regulator So, maybe this resistor is shorted and not providing any resistance to keep the voltage in check ? proper 6v regulator Maybe a new 6v 1 wire regulator that grounds to the frame or an in line regulator ? Thanks So, Very Much ! Link to comment Share on other sites More sharing options...
Moderator Airhead Posted March 31, 2010 Moderator Share Posted March 31, 2010 cursory regulator So, maybe this resistor is shorted and not providing any resistance to keep the voltage in check ? proper 6v regulator Maybe a new 6v 1 wire regulator that grounds to the frame or an in line regulator ? Thanks So, Very Much ! Read this topic http://www.electrexworld.co.uk/rg06-regulator-1325-0.html Link to comment Share on other sites More sharing options...
Vmax540 Posted April 1, 2010 Author Share Posted April 1, 2010 Oldgit. Thanks for the help ! Here is another reason for high voltage that was given to me by a guy who was a dealer tech. in the 70's ! THE PROBLEM COULD BE IN THE HEADLIGHT SWITCH. NOT MAKING CONTACT TO SEND THE CURRENT BACK TO CHARGE THE BATTERY. IN THE DAY IT WAS VERY COMMON FOR THAT TO HAPPEN. THE CONTACT BOARD WOULD " BOW " , THE PLATE THAT MOVES FROM ON TO OFF WOULD NOT BE MAKING CONTACT, THUS ALL THE AC CURRENT WOULD FLOW TO THE HEAD LIGHT. DO THE TROUBLESHOOTING WITH A VOLT METER. I THINK ONE WIRE WILL GO TO THE REGULATOR/RECTIFIER. OR MAYBE THERE IS ONLY A RECTIFIER. THE BATTERY HAS TO BE " GOOD " TOO! Link to comment Share on other sites More sharing options...
Novabiker Posted July 26, 2011 Share Posted July 26, 2011 Hello VMAX540, I am having the same problem on my 1973 DT3 and was wondering if you found a fix. Heres what I have done for troubleshooting so far: - checked the battery voltage with the engine not running and its at 5.9 volts - checked the charge rate and with the engine at 2500 RPM its at 6.1 volts, at 5000 RPM it goes up to about 6.9 volts. - checked the AC voltage at the yellow wire coming from the magneto with the engine running and key in the "lights on" position. At 2500 RPM the voltage is about 12.5 volts and at 5000 RPM its around 16.5 volts. The yellow wire remained connected during the check. - checked AC voltage with the key in the "lights off" position and the voltage is around 16.5 volts at 2500 RPM and 28 volts at 5000 RPM. - checked the AC voltage at the headlight blue wire and at the headlight socket and the voltage is the same as above. - checked the continuity of the handlebar headlight switch in both the high and low positions and it seems to be correct. I did not have a sealed beam headlight installed during the above checks since the bulb was blown and I did not want to risk putting in a replacement while I had such high voltage. I have read the threads on installing a 6V voltage regulator and will consider that as an option but the 'purist' in me says that if it didn't need one coming out of the factory then I should be able to restore it to the same condition. (but I do have a limit on how much pain and suffering I'm willing to endure to make that happen Would welcome help from anyone who has any ideas on other trouble shooting I can do to find and fix the problem. Link to comment Share on other sites More sharing options...
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