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By schoschi12
#9274
Hi Everyone

I'm rebuilding an Enfield Bullet 350, 1991 for the indian market. It has benn disassemled since 1995. Now about the current problem: when connecting the battery and turning on the ignition, the ammeter goes full positive and starts to smoke. After disconnecting the batrery, I measured no resistance between the two poles (obviously). I could easily isolate the alternator as not beesing the problem, but struggle to isolate anything else. Ground seems to be positive, but I could be wrong about that as well. Does anyone have any tips on how to search for the short circuit by measuring? I already checked everything I could visually.
Thanks everyone in advance, I really appreciate your help
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By stinkwheel
#82662
With the ignition on, but nothing else, the only thing that SHOULD be drawing power is the ignition coil. So here's an idea.



Firstly, disconnect the ignition coil. Now nothing should be drawing power. But you have a short. So, connect a bulb holder and bulb in series with the battery positive. An indicator works well for this.



What should happen now is any short to earth beyond the battery will make the bulb light up which introduces a load in the curcuit and prevents fire/smoke/melting. So you can turn that ignition switch on, if a short is present the bulb will light. Now start wiggling wires and disconnecting parts of the wiring one at a time. When the bulb goes out, you are in the right area.



It is a negative earth.



Now here's the rub though. What is your main fuse doing while there is smoke coming out of the ammeter? It should have blown. Suggests there isn't one or if there is, it's been replaced with a bolt/wrapped in tinfoil or similar. So what else has been messed with?



If I was a betting man though, I'd disconnect the reg/rec early-doors and see if your problem goes away.
By Andy C
#82664
If the ammeter goes "full positive" and starts to smoke something is fundamentally wrong. Clearly a heavy current is going through the ammeter, but why is is showing positive? if current is being drawn through the ammeter then it really should show full negative as the current is drawn from the battery. As Norm says, should be negative earth, so it looks like you have the battery the wrong way around. Try changing to negative earth.
By schoschi12
#82767
Thanks everyone for your help. As stinkwheel suggested, the problem seems to be caused by the reg/rec. Is it possible that I bricked the reg/rec by connecting the battery the wrong way?
There is a resistence of about 300 Ohm between (+) and (-) DC, does that sound right? And am I correct in assuming that with the diode setting on the Multimeter, the two AC poles should point towards (+) and away from (-). In my unit, one AC pole shows "being a diode" in both directions, which can't be correct, right?
By schoschi12
#83257
So the problem definitely was the reg/rec. Exchanging it solved the problem and I now have a working spark.
Again thanks to everyone for your help and suggestions.
By schoschi12
#91065
Hi everyone

Thanks again for sour help so far, but sadly things still aren't working as expected. I'm getting a spark, so there's that. However when the contact breaker is closed and ignition is on, the battery is drained rapidly (around 1V/30sec). Now from my understanding, the connection goes (+)battery - > ignition switch - > contact breaker - > primary coil - > (-) battery. Is that more or less correct? The resistance of the primary battery is around 3.4Ohms.
So my question is: what is it I got wrong about the connection of the primary coil? Because if my assumption is correct, obviously a huge current would flow, but that can't be right, can it?
Thank you in advance for your help, especially since these probably are rookie questions.
User avatar
By Wheaters
#91070
Have you tried a new points condenser? It's possibly shorted out. Or possibly the points themselves shorting to earth.
By Daiwiskers
#91072
Positive from battery to ignition switch to positive on coil negative from coil to points to earth through back plate and condenser

You will have other connections in there but a basic ignition system works as above

If you're running positive to Point's there's your problem
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By PeteF
#91073
What condition is the battery in? If it's on the way out it will discharge quickly.

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