pugslee Posted July 26, 2011 Report Share Posted July 26, 2011 Hi Guys I am new to the site and wondered if anybody has fitted lights to a bultaco. I have just purchased a 350 sherpa 78/79 frame no 199 and wondered if anybody could advise me on lights I have purchased the brake switch and front/rear lights and have got a wiring diag from bultaco uk. iam told they are notourious for problems with lights and blowing bulbs. looking on the wiring diag i need a resistor, where do i get one and what voltage bulbs do i need 6v or 12v Thanks for any help given. Quote Link to comment Share on other sites More sharing options...
pschrauber Posted July 26, 2011 Report Share Posted July 26, 2011 (edited) Yep, I do. Not that I like the full electrical equipment very much but I need this for getting the bike road registrated. First then I can get a classic / vintage bike rating and an insurance for the bike. The Bultaco uses 6V, the FEMSA or MOTOPLAT ignition and generator is "rudge" in the delivery of electrical power, (not continouos and in variable power depending of thr rpm), so you need something to get rid of the power peaks otherwise as you already mentioned the bike will eat bulbs frequently. The Bultaco Sherpa used and uses this resistor which is a very simple one. The resistor has to be mounted to the frame and connected to the rear light. Beware, when getting old and rusty this device will not work proper any more. BTW: The original switches and kill botton wich came with this trials bike where very simple and did not work "so good" either they failed often and break down very easy. Bultaco had some better switches and an electronic regulator too, but this electrical equipment was used for the street and enduro bikes. Some Sherpas where fitted with the better equipment when flashlight are required for getting the bike road registrated, like in Germany, Austria and Netherlands I believe, ...). This equipemt was taken from the Metrella (Bultaco streetbike models). The better original switch unit from the Metrella is: - Leonelli Art. Nr. 074 PA7 (complete switch unit with flash switch) Instead of the simple resistor the Metrella and the mentioned Sherpas got an regulator, the model that fits to the Sherpa is: - FACOMSA 6v - LIMIT - 45W, Volante Magnetico, Ref: 1300601 Both electrical parts work much better as the simple ones and are still contemporary. As a switch unit you can certainly take other units. To try a differnt regulator can be a problem for your generator/ignition or both or the different regulator. regulator and generator have to fit each other if not they can "destroy" each other. So I would be very carefully if someone offers you something completly different to your existing old original ignition/generator. There are replacement ignition/generator units available for them you can use a regulator that is recommended by the producer/seller. Hope this is helpful Edited July 26, 2011 by PSchrauber Quote Link to comment Share on other sites More sharing options...
woody Posted July 26, 2011 Report Share Posted July 26, 2011 Hi Guys I am new to the site and wondered if anybody has fitted lights to a bultaco. I have just purchased a 350 sherpa 78/79 frame no 199 and wondered if anybody could advise me on lights I have purchased the brake switch and front/rear lights and have got a wiring diag from bultaco uk. iam told they are notourious for problems with lights and blowing bulbs. looking on the wiring diag i need a resistor, where do i get one and what voltage bulbs do i need 6v or 12v Thanks for any help given. Just curious as to why you want to fit working lights - MOT? If so, you don't need them for an MOT, regardless of what a tester tells you. If you're planning on riding the bike in the dark, say plenty of prayers beforehand and keep your fingers crossed when riding, as they are about as effective as a candle and things always get exciting when you throttle off for bends on unlit roads - the drop in revs dims the lights, just when you need them most... 1 Quote Link to comment Share on other sites More sharing options...
pugslee Posted July 28, 2011 Author Report Share Posted July 28, 2011 Thanks for the great reply and photos. Can you tell me how the resistor wires in to the back light. i have three wires, one is earthed to the frame and the outher two feed running light and brake light. am i right in thinking that it joins to the live feed going to the running light. also can you tell me what color wire i use for the lights from the mag as i seem to have 2 live feeds for lighting. Thanks Quote Link to comment Share on other sites More sharing options...
pschrauber Posted July 30, 2011 Report Share Posted July 30, 2011 (edited) I have a colored wiring diagram I made myself to get the electric sorted, sadly it is in German, but I beleive it is easy enough to understand as the wires are drawn in color, here a scan of the drawing: # 8 is the resistor # 9 is the rear brake switch #10 is the rear light, Masse = earth/frame R Edited July 31, 2011 by PSchrauber Quote Link to comment Share on other sites More sharing options...
cunpr Posted August 3, 2011 Report Share Posted August 3, 2011 Dear Poster, This may help but you will need to run through the pages and translate from the german. To get around the blowing bulbs (too much electricity at high revs) and dimming lights when idling fit one of these ULO EBL boxes. They are contemporary and my Frontera had one. It has a small battery to keep the lights bright and a regulator to protect the bulbs, also has a blinker built in. I've seen them advertised on e-bay as well. Should be all you needs in one box. hope it helps. Regards Paul C http://www.herculesig.de/ULO_d.html http://www.kreidlertreff-giessen.de/Ulo%20Box%20801%2000%20Montageanleitung.pdf http://www.kreidlerparts.com/scripts/part_detail.asp?id=346 Quote Link to comment Share on other sites More sharing options...
happyhenry Posted January 1, 2013 Report Share Posted January 1, 2013 (edited) I have a colored wiring diagram I made myself to get the electric sorted, sadly it is in German, but I beleive it is easy enough to understand as the wires are drawn in color, here a scan of the drawing: # 8 is the resistor # 9 is the rear brake switch #10 is the rear light, Masse = earth/frame Rücklicht = rear light Kupplungs- Stecker = plug connector Bremslicht = brake light Rückleuchte = rear light The green wire goes to the brake bulb The black wire goes to the rear light bulb The colors of the wires are right exepct purple which is white! The diameter of the cables/wires is around 2.3mm (= 1,5mm²) You may attach an additional plug connector attached on the underside of the fender for easy assembling of the rear light where the cable/wires had to be solded to the bulb socket. I am currently putting my Model 85 Alpina on the road and have wired it from scratch as the diagram above - which is basically what is in the Alpina manual supplied by Bultaco UK. However, I can't for the life of me see how this circuit makes the brake light work - it is on all the time (at full power) because the circuit is never broken by the brake light switch. The resistor is bypassed, the green is constantly connected to the bulb, as is the earth through the lamp body! The brake light switch merely duplicates the bulb circuit in parallel. Surely, the brake light switch needs to make and break the green wire between the resistor and the light unit. in which case the resistor is in parallel with the brake light bulb when the circuit is made by the switch. Which should reduce the peak voltage to the bulb. In addition, the green wire - which is the earth end of the ignition circuit, is earthed solely through the resistor. Which is known to be a dodgy old item in the first place! I'm more than tempted to splash out on the Electrex system and have a regulated 12V AC lighting circuit as well as electronic ignition. But the £230 price tag is a bit salty. Has anyone got a brake light to work using this wiring diagram? Edited January 1, 2013 by happyhenry Quote Link to comment Share on other sites More sharing options...
pschrauber Posted January 1, 2013 Report Share Posted January 1, 2013 I am currently putting my Model 85 Alpina on the road and have wired it from scratch as the diagram above - which is basically what is in the Alpina manual supplied by Bultaco UK. However, I can't for the life of me see how this circuit makes the brake light work - it is on all the time (at full power) because the circuit is never broken by the brake light switch. The resistor is bypassed, the green is constantly connected to the bulb, as is the earth through the lamp body! The brake light switch merely duplicates the bulb circuit in parallel. Surely, the brake light switch needs to make and break the green wire between the resistor and the light unit. in which case the resistor is in parallel with the brake light bulb when the circuit is made by the switch. Which should reduce the peak voltage to the bulb. In addition, the green wire - which is the earth end of the ignition circuit, is earthed solely through the resistor. Which is known to be a dodgy old item in the first place! I'm more than tempted to splash out on the Electrex system and have a regulated 12V AC lighting circuit as well as electronic ignition. But the £230 price tag is a bit salty. Has anyone got a brake light to work using this wiring diagram? These are pull switches for the brake light, there where two types: - one attached to the rear brake cable on the left side where the cable hose is mounted to the swing arm and - one attached to the right side mount of the cable hose of the rear brake cable where the mount is attached to the frame Which one? To the circuit there is a resistor interconnected (#08) this resistor will be bridged over by the rear-light switch. If not bridged over the resistor will "eat up" the electrical energy. Quote Link to comment Share on other sites More sharing options...
happyhenry Posted January 1, 2013 Report Share Posted January 1, 2013 These are pull switches for the brake light, there where two types: - one attached to the rear brake cable on the left side where the cable hose is mounted to the swing arm and - one attached to the right side mount of the cable hose of the rear brake cable where the mount is attached to the frame Which one? To the circuit there is a resistor interconnected (#08) this resistor will be bridged over by the rear-light switch. If not bridged over the resistor will "eat up" the electrical energy. Hi pschrauber, I may be confused here because I'm used to wiring older bikes that have rectifiers, regulators and batteries. I'm not used to AC direct lighting - though it should be simple because it is still only about making circuits. I have wired my Alpina exactly as the diagram and have only managed to run the bike for a short time before losing all spark. I have a brake light switch attached to a bracket on the left hand side of the swinging arm and activated by a spring attached to the rear brake rod - there is no cable on this model. There is no doubt that the brake light is in circuit all of the time. It seems that you are saying that the resistor 'eats' the current to stop the brake light illuminating and that the brake switch bridges the resistor to allow the brake light to illuminate. If this is the case, then the resistor is providing no protection for the brake light bulb. I thought it was there to do that job, not to act as a permanent heat sink to be bridged only when the brake is applied. No wonder they have a reputation for failing. Additionally, the green (power) wire from the alternator makes the ignition circuit. With no lights it would be 'earthed' to the body of the HT coil. With lights it is 'earthed' via the resistor to make the ignition circuit complete. If the resistor fails then there is no ignition - except via the brake light bulb when the brake pedal is compressed?! I need help to get my head around this! Henry Quote Link to comment Share on other sites More sharing options...
pschrauber Posted January 2, 2013 Report Share Posted January 2, 2013 (edited) I believe the resistor set up, (look up at the first photo in post #2 (the edged plate with a kind of a coil)), is a kind of a archaic predecessor of a voltage regulator taking away any voltage peaks produced by the generator of the ignition. Therefore it's permanent on, when the circuit of the brake lamp is closed by the switch the electricity just takes the "easier" route and the bulb will shine quite bright. You can mount a regulator instead that will fit in voltage and power, (see the third photo of post #02 for the regulator of Femsa (Spain)). If you have difficulties to get this unit you might can take the regulator made for Simson bikes, (Simson the former East German bike factory, Simsons have the same delivery of voltage and power, 6V and 45W)). This is a guess I' haven't done this and you have to check out ground first, (if it's - or +!, I haven't done this) A ressource is here: http://www.moped-wer...tt-F-Simson-AWO Otherwise You wan't to ask Powerdynamo f.e. if they have any regulator that works with the original ignition. If not you will have run the bike without any and the risk the of replacing bulbs frequently. I hope this helped ??? Patrik Edited January 2, 2013 by pschrauber Quote Link to comment Share on other sites More sharing options...
happyhenry Posted January 2, 2013 Report Share Posted January 2, 2013 Thanks Patrik, I have the resistor as in your picture and now understand how it is meant to work. You are right, this is a crude system. I will carry on to see if I can make this work as designed - otherwise I'll look for an alternative method. Thanks for your help. Henry Quote Link to comment Share on other sites More sharing options...
happyhenry Posted January 2, 2013 Report Share Posted January 2, 2013 Patrik (and anyone else who has been following this - and hasn't yet lost the will to live...), Having installed new points, condenser and HT coil and using a auxiliary fuel bottle, I got the bike running today - it starts second kick every time much to my amazement. Lights and kill button work, the horn doesn't - but hey, I'm making progress. However, the brake light is still permanently on - until I press the brake pedal - when it goes out!! I wonder if the original Bultaco brake light switch was normally made (closed) and opened when switched. This would explain the peculiar wiring as the current normally took the easy route through the made (closed) switch, and was forced through the brake light bulb when the switch was activated and the 'easy' circuit was broken. I will experiment tomorrow by reversing the direction of the switch to face backwards, towards the rear wheel spindle so that it is held in the made (closed) position until the brake is applied and then the circuit is broken - and the light comes on! What could possibly go wrong? Left- handed kickstart; right handed prop stand; backwards electrics - it all makes sense now! Cheers Henry 1 Quote Link to comment Share on other sites More sharing options...
pschrauber Posted January 2, 2013 Report Share Posted January 2, 2013 ... I wonder if the original Bultaco brake light switch was normally made (closed) and opened when switched. This would explain the peculiar wiring as the current normally took the easy route through the made (closed) switch, and was forced through the brake light bulb when the switch was activated and the 'easy' circuit was broken. ... I confess I have never have tried the rear brake switch elsewhere or did a check with a multi meter, (there was no need so far). It may well be possible that the system works "in the other sequence". This very archaic looking electrical component on the plate, in my eyes, very unique as I never saw this on any other bike ... elsewere I believe I will not think about it, probably we can assume it works when doing the opposite. 1 Quote Link to comment Share on other sites More sharing options...
seakayaker Posted January 19, 2014 Report Share Posted January 19, 2014 Hi, I've been reading through this topic. I am also in the process of making up a lighting/wiring harness for my Alpina. I have a Motoplat 6 pole points generator. I am not going to install a battery ( as i think was originally fitted). But need to know what ( or how to find out) which lighting coil should supply which part of the lighting circuit... I have 6 wires coming from the Stator. one to earth, one to the ignition coil. one I assume goes to the ignition/kill switch, the other three? H/light? taillight? brakelight and horn? If i get overvoltage bulb blowing issues: can i just fit 12volt bulbs. any advice much appreciated, SeaKayaker Quote Link to comment Share on other sites More sharing options...
matador107 Posted January 19, 2014 Report Share Posted January 19, 2014 The original setup using the voltage regulator did use a brake light switch that had a normally closed contact, it opened when brake lever was operated.Bultaco wiring diagrams can be frustrating,I have a PDF copy of my own design if anyone is interested. Send me your email request to, mwe@optusnet.com.au Martin Quote Link to comment Share on other sites More sharing options...
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