One for the very clever people

[Interpol2471]

And yes before anyone says anything this is a general question for 12v Zener / rectifier charging systems on British Bikes not Rotary...I know..DOOH!!!I have a certain bike that is being very naughty at present and has a very unstable 12v causing the indicators to flash quickly when running etc. I have since fitted a new battery (sealed type) and a brand new zener diode. Still the same result so I am thinking of changing to one of the new Podtronic or Boyer Power Box type set ups to get rid of the zener and rectifier which is also the old Lucas type to hopefully cure this.My question is I have a charge light same set up to my T150V on the instruments fed from the Brown / white (zener) wire from the centre terminal of the rectifier can I use this as the postive feed output of the new combined unit and will the charge light react the same?All the instructions on the Podtronic type units state to best connect direct to the battery and Boyer advertise a unit that has a charge light feed, so which would be best for my use as someone must have spent some time on this before?I am hoping I can just use a Podtronics unit and connect straight onto the brown/white wire and to earth job done leaving the zener in circuit to look pretty as I guess it will not do anything except drop extra if required.Many thanks and please remember Army so I need clear loud instructions

[Interpol2471]

Oh and before it is pointed out I used the T150V light as an example of what I have I know this is a multifunction light on the Triumph for Ignition on and the oil pressure where as on the naughty bike this is purely for charge warning.To follow when the bike is running the charge warning light flashes on every now and then but of course improves when you put on the lights to increase the load. Thus why I fitted a new zener thinking that was the issue checking for correct polarity as this bike is negative earth.On a digital multimeter you get a very unstable output across the battery terminals I do not have an analogue meter at hand at present but will have in the week.

[FloridaMike]

You're going to get an unstable reading with a digital meter even if everything is OK, their response time is almost immediate.If the battery is good (how old is it?) it should "damp" or stabilize the reading somewhat. I'd check all the connections, make sure nothing is loose or corroded. The random flickers of the charge light would tell me to look for a loose connection. The cessation of the flickering when you turn the lights on (which adds the output of the four lighting coils) points me to inspect the connections of the two day coils.You just might have a bad stator, check continuity (use ohmmeter, engine not running, wires disconnected) between the ground wire of the stator and the day coils output wire, wiggle the wires and see if the reading changes, if it does, something is loose.Zeners are either good or bad, I've never seen an intermittent one. Remember to put a dab of heat sink grease under it, and the tightening torque is an absolute maximum of 2.5 foot pounds (that's two point five), I'm more comfortable at 2.0 foot pounds because if you snap off the stud, you've ruined the Zener. (ugh)Radio Shack sells cheapo voltmeters ("analog VOM") for a whopping $5 here, that's a hard price to beat. They may have the heat sink grease, but chances are they won't know what it is and will try to sell you a cellphone instead, so your bet bet might be a computer repair shop (not a place that just sells computers, someplace that actually fixes them) because heat sink grease is also used under CPUs - it is a white gooey stuff which you do NOT particularly want to get on your fingers because it is mildly carcinogenic. Use finger cots. You don't need much, just a dab. Talk nice and you might get some free.Best,Mike

[FloridaMike]

Just saw that the battery is new - disregard that part.Best,Mike

[Interpol2471]

Thanks Mike but yes the battery is good as above and I did use heat sink compound on the zener.I have also checked the alternator readings and all connections by buzzing them out thus the confussion on why I am seeing I expect in excess of 15v across my battery and thus the fast flashing indicators as an obvious indicator that the voltage is too high?

[Dell Boy]

You could have the wrong wattage bulbs in the indicators. Worth checking.I would replace the rectifier with a solid state one from Maplins. About £2.00 each so buy a couple.See how you get on with that.I can see no reason to go the Podtronics route.Derek F.

[johnbirchjar]

I supose you have tried a new flasher unit? (you didn't put it on your "things I have tried "list)rgds,J.B.

[Interpol2471]

Hi John I think I may have found the issue but TBC The zener on this bike is situated in the lower of the front yokes does it have a good earth return path through the head bearings and frame....NO..!!!!Has it got worse after fitting new greased head bearings after Christmas ..Yes... Time for some earth wire I think and I may well fit the solid state rectifier as well as I bought a bag full some time ago from my local Maplins Cheers

[FloridaMike]

Yep, bad and intermittent ground through the head bearings will do this! And yes, you really DO want a ground wire from the forks and heat sink to the chassis.Suggest you hold off on the Maplins diode conversion simply because you want to check/change one thing at a time. If you make a bunch of changes all at once, it is possible that you may not cure the original problem, and you might be installing new ones!If the ground wire cures it, then, if you really want to, do the Maplins diode job.Best,Mike

[Interpol2471]

Thanks all and I will do one at a time Mike and report back.Thanks again

[Interpol2471]

Well after some head scratching and fitting new solid state rectifier and a lot of good earths still the problem sits there laughing at me....So what's this Lucas 3AW light control module up to in the charge circuit.. Oh I see it's there to play up and cause my fault......who would have guessed the charge light control relay was failing and shorting out Solid state replacement ordered now

[Interpol2471]

I also found the bike did not like the new sealed modern style battery and a lead acid old style dropped the volts to a nice 13.5V, who would have guessed.A Wassel Zener was also changed for a Lucas one and that also helped so she is as good as gold now.Thanks all