RAW1969 Posted February 11, 2020 Report Share Posted February 11, 2020 Hi all. Back seeking more help please. 1967 Vitesse 2L (mk 1). After a short lay up at the end of last year (after some big welds) my Vitesse won’t start. Having tried fresh fuel & damp start I turned to the electrics. Found no spark having taken a plug lead off and held near the block. So went back to the distributor. With cap off there’s no spark across the points. I’ve measured 12v at the coil (and 3 ohms across it). Bought a new condenser. With that in I have 12v at the distributor LT feed on the distributor housing and at the other end of that lead in the distributor. (With the old condenser in I don’t). Still no spark though. I’ve also checked the earth connection inside the distributor which is ok. At this point I’ve run out of ideas! The thing I’m not sure of is there’s an insulating washer under the nut on the post for the live contact (and condenser lead) and the brass tabs on those leads have holes big enough not to contact the post. So wondering how the LT live feed connects to the points base plate? Maybe a daft question as the set up had worked previously. I’ve only got a loose grasp on what’s meant to be going on here which makes diagnostics doubly difficult!!! Any pointers as to what might be going wrong or further measurements to check will be gratefully received. The battery’s Ok also. I’ve caused a spark in the distributor with a screw driver to earth (by mistake) but shows there enough umph there to get a spark if everything else is doing what it’s meant to? thanks in advance Richard Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 11, 2020 Report Share Posted February 11, 2020 the eyelets on the coil points lead and the condenser wire all fit on top of the the eye on the end of the points spring the plastic bush fits through all 3 to insulate them from the base plate stud , fit the bush, washer and nut to hold it all down . Pete Link to comment Share on other sites More sharing options...
JohnD Posted February 11, 2020 Report Share Posted February 11, 2020 Richard said, " After a short lay up at the end of last year (after some big welds) my Vitesse won’t start." Did you disconnect the alternator? Without that the diodes can be fried by welding. ?? condensor? It's a sort of diode. John Link to comment Share on other sites More sharing options...
RAW1969 Posted February 11, 2020 Author Report Share Posted February 11, 2020 Sorry - should have said - was welded professionally. I drove it home afterwards so something stopped working whilst it was standing in the garage at home (waiting for paint and sills to go back on). I will double check the connections / insulation on the spring eyelet. Should the base plate have 12v on it through the condenser then? thanks Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 11, 2020 Report Share Posted February 11, 2020 the condenser bridges the points to stop arcing (connects the feed and earths via its case) think the base will as an earth show coil voltage if the points a re open , do check the points a re clean and do open and close as the cam rotates Link to comment Share on other sites More sharing options...
dougbgt6 Posted February 11, 2020 Report Share Posted February 11, 2020 2 hours ago, JohnD said: condensor? It's a sort of diode. Condenser is an old fashioned term for what is now called a capacitor. It sits across the points as Pete describes to prevent arcing. Capacitors hold electrical charge. Diodes allow current to flow in one direction only. You should be able to prise the points apart with an insulated handle screw driver and see the points spark. Doug Link to comment Share on other sites More sharing options...
JohnD Posted February 12, 2020 Report Share Posted February 12, 2020 doug, A condensor/capacitor allows current to flow in neither direction, it builds up charge when a potentialis across it, which is then discharged when the poetential drops again. So it is a "sort of diode". And, it does so by having a "dielectric", an insulator, between two conductors which may be plates, or in the usual capacitor/condensor very thin sheets of metal foil, rolled up with equally thin dielectric layers, to make a small component. Modern 'condensors' which we may buy for our dizzies, are notorious for breaking down which means that the dielectric ceases to insulate and current does flow, shorting the points. This damage might be caused by the pulses in the loom, if not disconnected - the rectifiers (diodes) in an alternator certainly are! In my ignorance, I asked if this could be the cause of Richard's problem. I'm grateful for your description of the function of a consensor in a dizzie, but you haven't answered my question. JOhn Link to comment Share on other sites More sharing options...
RAW1969 Posted February 12, 2020 Author Report Share Posted February 12, 2020 Thanks all. Diodes / capacitors aside for a moment - It’s the final point in Doug’s post I’m missing. I can’t seem to see a spark over the points when opening them with a screw driver. Will try again with something plastic to make sure I’m not accidentally shorting something else! But failing that any ideas why I could get a spark from the coil feed (from eyelet to earth strap) but not over the points gap? I must be doing something wrong and/ or misunderstanding what I’m seeing!? thanks Richard Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 12, 2020 Report Share Posted February 12, 2020 have known points to decide to breakdown and pass nothing try a new set Pete Link to comment Share on other sites More sharing options...
dougbgt6 Posted February 12, 2020 Report Share Posted February 12, 2020 1 hour ago, JohnD said: So it is a "sort of diode". Unusual for you John, but this is not true and will confuse anybody unfamiliar with electrics/electronics. Doug Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 12, 2020 Report Share Posted February 12, 2020 as many of the repro aftermarket condensers have diddly squat inside , what ever you call it could be wrong if we take a vote sorry John, not a sort of diode or even well sort of ha !! there have /has been some terrible points/ condensers/ rotor arm available that cause a lot of grief, luckily it seems to have improved recently, well its dropped off problems on here pete 1 Link to comment Share on other sites More sharing options...
Don Cook Posted February 12, 2020 Report Share Posted February 12, 2020 Anyone up in Manchester that could loan Richard a spare distributor? I always have a spare in my boot, all fitted up ready to hook up, other end of the country though! Link to comment Share on other sites More sharing options...
NonMember Posted February 12, 2020 Report Share Posted February 12, 2020 3 hours ago, JohnD said: So it is a "sort of diode". In so far as the etymology of the term "diode" merely means "thing with two connections", you are right. In every other respect, though... A silicon diode is a solid-state component that serves the same purpose as a "diode valve" (a thermionic valve with two electrodes, one hot and one cold), which was to explicitly allow current to flow in only one direction. A component that does not allow flow, and does not distinguish based on direction, cannot in any sense be called "sort of" a diode by that definition. And since that definition is the one you will find in dictionaries (because they deal with the language as used, not the etymological relationship to dead languages that hardly anybody uses any more), that's the definition that matters. 1 Link to comment Share on other sites More sharing options...
NonMember Posted February 12, 2020 Report Share Posted February 12, 2020 3 hours ago, RAW1969 said: Thanks all. Diodes / capacitors aside for a moment ... any ideas why I could get a spark from the coil feed (from eyelet to earth strap) but not over the points gap? I must be doing something wrong and/ or misunderstanding what I’m seeing!? Can you clarify what you mean by "eyelet to earth strap"? Was that a case of accidentally shorting the coil -ve to ground? If so... To get a spark, both HT (plugs) and LT (points or screwdriver tip), you need the flyback voltage from the coil. This is achieved by building up a decent current in the coil primary (LT side) and then interrupting this current. Your screwdriver to earth achieves this nicely. The points should achieve it if they close properly, conduct properly, and open properly, and are connected properly to the coil. Also, nothing else is providing an alternative current path. Any one of those five conditions being untrue will prevent the spark. 1) close properly - you may have them set too wide so that they never close, or there may be something holding them open. You can usually tell from inspection. 2) conduct - if the points are heavily pitted or covered in muck (spilled oil, protective wax, WD40) then they won't form a proper electrical connection when closed. A simple test is to put a light bulb in place of the coil and rotate the distributor. The bulb should illuminate and extinguish as the points close and open. 3) open properly - similar to 1, you might have set them too narrow 4) connected - you asked about the plastic washer. The electrical connection from the points to the coil runs along the spring to the LT wire. This must not be shorted to ground, and the pin that it fits on is grounded. So the assembly order must be: plastic top-hat washer, then spring, then LT ring terminals, then another plastic washer (small end down this time) then the nut. 5) alternative path - if you're missing one of the plastic washers, the LT wire is connected to ground. If you have a metal screwdriver wedging the points open against the distributor body, the LT is connected to ground. Hope that gives you some things to look at. 1 Link to comment Share on other sites More sharing options...
RAW1969 Posted February 12, 2020 Author Report Share Posted February 12, 2020 Hi yes screw driver from the eyelet on the wire from the coil to the screw holding the earth wire to the distributor body got an accidental spark.(I had forgotten the ignition was on by then). Plenty more to think about now thanks. Can I just ask though. If the eyelets are insulated from the spring post on which they sit how is the current conducted along the spring? It’s maybe that connection I’ve lost in my meddling? thanks! Richard Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 12, 2020 Report Share Posted February 12, 2020 the eyelets must sit on top of the contact spring , so from the base plate upwards you should have plastic bush, the spring eye, two wired eyelets, plastic bush washer nut the cotton braided earth lead connects the moving top plate to the base casting fixing screw pete 1 Link to comment Share on other sites More sharing options...
RAW1969 Posted February 12, 2020 Author Report Share Posted February 12, 2020 <“Sound of penny dropping”> Think maybe the insulating bush through the spring is making the eyelets sit up away from the spring. Will check that. Feels like progress without even going near the garage 🙂 Really tricky putting these things into words! thanks all. Will report back once re-examined with newly acquired information! Richard Link to comment Share on other sites More sharing options...
JohnD Posted February 12, 2020 Report Share Posted February 12, 2020 No, I don't know electronics, and if a condenser lsnt any sort of diode, well, its a small electronic component. But I asked a question, could the welding have damaged it, and was hacked off by Doug's unhelpful response. And no one else has even tried to answer it. So let's try again. Could "heavy welding" damage a condenser? John Link to comment Share on other sites More sharing options...
Paulfc Posted February 12, 2020 Report Share Posted February 12, 2020 Yes, it could. But Richard says he drove home so it seems it’s unlikely to be the cause. Paul Link to comment Share on other sites More sharing options...
NonMember Posted February 12, 2020 Report Share Posted February 12, 2020 1 hour ago, JohnD said: Could "heavy welding" damage a condenser? Pretty unlikely. The problem with welding damaging alternators is because they contain some relatively sensitive silicon semiconductor bits. High voltages, even at low current and for very short times, can destroy such items. On the other hand, high voltages are exactly what the condenser is there to handle. The voltages aren't applied directly, of course, but through complicated inductive coupling from the arc generated by the welder. Arcing is very bad for semiconductors but, again, it's pretty much exactly what the condenser is wired across in normal use. In fact capacitors (which, as has already been said, is the modern name for condensers) are fitted on the "outside world" pins of electronic circuits precisely to protect the delicate semiconductors from high voltages generated by static charge build-up. 1 Link to comment Share on other sites More sharing options...
dave.vitesse Posted February 13, 2020 Report Share Posted February 13, 2020 Firstly check the lead between the dizzy and the coil as this maybe open circuit or intermittent. With the Ignition on place the bulb on the neg - terminal of the coil and ground. The bulb should light when the points open and not when the points are closed. If it stay on all the time then check the dizzy/coil lead and the connection to the points in the dizzy. If it doesn't light then disconnect the dizzy lead, if it then lights the fault is in the dizzy. Checking the points - Place a bulb across the points. With the ignition turned on open and close the points. With the points open the bulb should light. With the points closed the bulb shouldn't light. If the bulb doesn't light with the points open then either the points are shorted to ground or the condenser is faulty or you don't have a connections between the dizzy and coil. Plus check the lead between the points and the terminal on the side of the dizzy as this can break inside it's insulation. Try the bulb on the points direct and then on the side terminal to see if there is any difference. If it lights all the time on the dizzy terminal, with the points closed, then the lead maybe the problem. Sorry it's long winded, just trying to cover all angles. Dave 1 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 13, 2020 Report Share Posted February 13, 2020 heavy welding can upset many unrelated problems we had 8x4 trucks where all 4 front wheel cassette bearings had welding damage to the bearing tracks and rollers due to poorly earthed welding on the chassis , it happens theres one oddity here it drove then didnt , what has happened in between ??? has anything been touched , what was the last action taken before it stopped ??? Pete Link to comment Share on other sites More sharing options...
dougbgt6 Posted February 13, 2020 Report Share Posted February 13, 2020 13 hours ago, JohnD said: was hacked off by Doug's unhelpful response. My response was not unhelpful, I was simply pointing out your mistake. Doug Link to comment Share on other sites More sharing options...
johny Posted February 13, 2020 Report Share Posted February 13, 2020 Can happen. Even I made a mistake once! 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 13, 2020 Report Share Posted February 13, 2020 same mistake as when trapped wind turns out as a disqualification and none of this starts the car pete 1 Link to comment Share on other sites More sharing options...
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