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[steve H]

dear all, especially Alan R, I've checked the voltage at the coil + terminal (ignition on, multimeter earthed to a neighbouring bicycle, a classic BSA of course) and get a reading of 0.2 volts. Is that enough? By the way, I have a Boyer electric ignition box rather than points.


Is the coil the problem? Could the Boyer be the prob?


Thanks for your help

[Midge]

There is a fault finding chart on the Boyer website but I would have thought you should have 12V at the coil+ As far as I am aware, the only things in line between the coil and Battery is the fuse and Ignition switch.

[Norm]

 Steve,


    I can't imagine why you would be testing with the negative of your mulitmeter to another bike, maybe some trick I'm unaware 

[Alan R]

Hi SteveH ------------- OK, I've done some checking myself and it's not April 1st (but only just) so I'm assuming you are being up-front & genuine ??  Now one of the problems for us "long-time-on-bikes" guys is we tend to forget some people have little or no understanding of basic engineering termanology ( yes--it's an OLOGY !!). So Steve---I'm not being sarky or rude here,  OK ?? but what do you, personally understand by the term "An earth return circuit" ??  I've spent 90% of my working life in what you might call"Engineering Diagnostics"---------------- ie fault finding and repair, and usually the most difficult part of the process is trying to understand what the owner/operator is actually trying to tell me.High power transmission cables, buildings etc are actually "earthed" or "grounded" by a big metal spike  with the return cable attached. However, in the case of automotive ( cars, bikes, trucks--but NOT fuel/flammable tankers) the electric circuit starts at the battery, lets say the +ve terminal,-----flows along the wires to the electrical item( Known as the "consumer") and then it needs to return to the -ve terminal on the battery. To save on costly wire going all the way back again as the frame or chassis is made out of steel (A conductor of electricity) the wire( or the consumer body) is attatched to the frame. The battery -ve terminal is attatched to the frame also and electrical"continuity" is maintained. This is known as a Negative Earth system  and is found on nearly all modern vehicles.   So with your test meter, remove the clip from the  trusty BSA and clip it to the -ve terminal of the battery. With the ign. switch turned on you should be reading battery voltage (12v nominal)  If NO then you have an"open circuit" ( break) in the system including the feed wire from the ign. switch, the switch itself or the electrical feed to the switch. If YES  then we'll need another page ---have a go and tel us what you now find 

[Norm]

 Alan,


     I did write up that I thought it might have been the first of April but I deleted it lol not wanting to offend. This is where I find multimeters are a pain and often give confusing readings, use a test light with a spike. Ony thing I use the meter for is testing the battery, charge rate from the alt and continuity testing of wires, every other step the test lights gives you an instant result without numbers flashing up and down on a meter

[Leon Novello]

I prefer the analogue meter, the indicator moves across the dial and stops on the reading, no staring at tumbling numbers, waiting for them to stop, then looking where the decimal point is and doing mental arithmetic to work out what it all means; in my case, still getting it wrong.

[steve H]

Dear all,


 


I've got to admit a great deal of ignorance as to any form of engineering, especially vehical electrics, why on earth is the return circuit also called the earth then?


Please bear with me!


If I link the multimeter to the coil + terminal and back to the battery - terminal, what king of reading should I get and what would it mean?


I suspect this is quite a small and easily fixed problem, so the last thing I want to do is have to get breakdown recovery to take it up to Dave Wicks (local Enfield dealer). All I need to know is how to diagnose the problem (unfortunately I am totally ignorant!).


 


Thanks

[Norm]

 Steve,


    If you don't know what voltage you are supposed to have you shouldn't be trying to work it out with a multimeter, get a test light from your local elcheapo shop, it is all you need and it will tell you straight away where you have power and where you don't. Then we can answer your questions

[Alan R]

Hello SteveH -------That's why we're here old son---to help you through that "barrier" and bring the sunny rays of knowledge into the darkness ( Actually it's snowing here in Shropshire----- but you know what I mean.) Now we are aware of your actual abilities/knowledge  it will help us to help you......good stuff, eh?? I'm fully in agreement with Norm on this one and from your point of view knowing the actual voltage will only complicate matters. So a test lamp it is then.      Incidentally, aren't there any local Enfield lads in the  Norfolk area who can call-in and give our Steve a practical hand ???                                                                                                 Another name used in the common return system eg in the space  vehicle programme or in heavy power transmission is a "Busbar". In those big switchgear cabinets that you see in large buildings, Hospitals etc, the actual bodywork is too thin to use as a return so they use strips of copper---typically 3mm or 6mm thick and of varying widths according to the power requirements. In the film Apollo 13 when things start going "Pear-shaped" you can hear Buzz Aldrin saying-----"Houston, we have a serious Bus-Under Volt"  which is their tech-talk for saying they've lost Electrical power.  So you now have a tenious link to the American space programme !!   Things you learn when owning an Enfield ??

[John L]

Steve H -


You haven't mentioned the year and model of the bike in question, nor the type of Boyer igntion fitted.


I presume your location is Norfolk, but whereabouts ?


Please help us to help you.


John L.