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    Headlight blowing

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    • O
      oldman last edited by

      Looks like my reg/reç has gone, keeps blowing headlight bulbs, am I right?

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      • J
        Jens Eskildsen last edited by

        Meassure voltage at reg/rec and battery while idling, and while at 5000rpm

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        • O
          oldman last edited by oldman

          Measured voltage at battery, 14.6v dc @ 5k, measured at headlamp, no dc voltage, ac 16v and rising with revs? Can't get to reg/rec this eve, visitors here and told I can't be rude!

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          • Calum
            Calum last edited by

            Yeah 16V sounds too much.

            Rectifier is just a bunch of diadoes though.

            Always Originate, Never Pirate!

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            • O
              oldman last edited by

              Think the reg side is working fine, it's the rectification that's failed, lighting coil produces a.c. voltage that should be converted to dc via rectification but it's not (as I understand it) , trying to get a reading at headlamp for dc voltage impossible, only a.c. there.

              Calum 1 Reply Last reply Reply Quote 0
              • Calum
                Calum @oldman last edited by

                @oldman I would have thought it would be D.C. but on the flip side there is no reason why it wouldn't tun A.C.

                I would have to check the wiring diagram to know what's gone wrong.

                Always Originate, Never Pirate!

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                • O
                  oldman last edited by

                  Sure I read that the lighting coil produces a.c., hence the need for rectification, no other way a.c. voltage could get to the headlight unless rectification failed I think, happy to be proved wrong though, different coils for the charging etc innit??😅

                  Calum 1 Reply Last reply Reply Quote 0
                  • Calum
                    Calum @oldman last edited by

                    @oldman But even if that is the case, 16v over the lights seems too much to me for a 12v bulb.

                    Always Originate, Never Pirate!

                    S 1 Reply Last reply Reply Quote 0
                    • S
                      scrimsmustang @Calum last edited by

                      @calum said in Headlight blowing:

                      @oldman But even if that is the case, 16v over the lights seems too much to me for a 12v bulb.

                      Yeah thats why the bulbs are blowing, mind you they will blow even if the battery is on its way out also. Even if reg/rec is good.

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                      • O
                        oldman last edited by

                        2nd battery fitted, new, so no issues there, should not be a.c voltage at headlight, blow within seconds as the revs rise high and low beam?

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                        • O
                          oldman last edited by

                          Replacement reg/rec arrived today, fitted, max voltage at headlight 14v, no blowing bulbs! Anyone know test procedure for old one? Would like to confirm failure because I am ****
                          Ta

                          Calum 1 Reply Last reply Reply Quote 0
                          • Calum
                            Calum @oldman last edited by

                            @oldman IIRC Haynes manual says impedance test across the unit should be x ohms.

                            I would need to look at it to get the right value though

                            Always Originate, Never Pirate!

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                            • O
                              oldman last edited by

                              Will have a look, have old version of manual, thought it said refer to manufacturer as you are too dim

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                              • O
                                oldman last edited by

                                My old copy of Haynes manual has no details to test, is there anything in the newer edition of the manual?

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                                • O
                                  oldman last edited by oldman

                                  On the old one the yellow cable has a mark that looks like carbonisation but no visible breaks in insulation (even with magnifying glass), could be insulation breaking down? Has not been pinched or damaged in any way and looks whole bar the markon the cable. Have seen before in commercial building applications, will check wiring diagram to identify cable and see if that could have caused failure, photo below.
                                  0_1510132463634_20171108_091326-979x1305.jpg
                                  Have cleaned off surface btw to show cable surface, black coating previously.

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                                  • F
                                    finnerz89 last edited by

                                    I doubt it's the cable, probably one of the internal components

                                    Current bikes:
                                    DT125X '07
                                    Street Triple R '11
                                    Aprilia ETV1000 '02

                                    Previous:
                                    DR650RSE '96
                                    FJ1200 '92

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                                    • Calum
                                      Calum last edited by

                                      As said, the rectifier IIRC is just a bunch of diodes. Diodes restrict current to one direction. So the rectifier will correct AC to DC. It's the regulator that should regulate the voltage.

                                      If the bulb is designed to dissipate 50 watts on a 14V DC supply, and you suddenly start feeding it 16V AC, well there is your answer.

                                      Always Originate, Never Pirate!

                                      F 1 Reply Last reply Reply Quote 0
                                      • F
                                        finnerz89 @Calum last edited by

                                        @calum yeah most likely a bridge rectifier, 4 diodes arranged to smooth out the sine wave.
                                        Regulator will drop the voltage by also dissipating heat which causes issues of its own

                                        Current bikes:
                                        DT125X '07
                                        Street Triple R '11
                                        Aprilia ETV1000 '02

                                        Previous:
                                        DR650RSE '96
                                        FJ1200 '92

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