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Electric challenge

Posted: Sun Aug 31, 2014 12:06 pm
by EnfieldbangDK
Greetings from the Kingdom of Denmark!

I own a 1957 RE Bullet - 350 cc - 6 volt.

Prior to riding it 4 months ago, there appeared to be little charge to the battery. However, then on a fast trip: 60 mph plus... it started charging and when I returned, the red cord i.e. negative (with Positive being the ground) had melted just at the battery connection and the battery was dead.

The fuse of 25 AMPS had not worked!

Upon checking for apparent shorts in the electrical system, I installed the new battery and a 15 AMPS fuse and connected with Positive to ground.

After 15 seconds, the unit holding the fuse started smoking and I quickly took the connections off...

What can be the problem?

The charging relay not functioning or are we talking about a malfunction in the stator/rotor at the primary drive?

I truly appreciate your ingenious comments.

Good Vibrations to all!

Electric challenge

Posted: Sun Aug 31, 2014 8:04 pm
by Bullet Whisperer
Usually the red wire is positive and this is the one that goes to earth on positive earth machines such as yours - are you sure you have connected up correctly - what colour is your other wire?

Electric challenge

Posted: Mon Sep 01, 2014 4:25 am
by EnfieldbangDK
Thanks for the interest. The other wire is Black. Awaiting your further reply with interest. Thanks in advance.

Electric challenge

Posted: Mon Sep 01, 2014 4:32 am
by Norm
you have a short somewhere and for some reason it isn't blowing the fuse. Something is not right with the fuse for starters, then look for the short

Electric challenge

Posted: Mon Sep 01, 2014 6:29 am
by Gwilly
Rectifier shorting back through the alt wiring or simply through the fixing bolt to earth.. Remove, sniff, examine and test if required..

Then move on to ignition switch.. Got to start somewhere..

Electric challenge

Posted: Mon Sep 01, 2014 7:18 am
by Bullet Whisperer
If the other wire is black, then that is the one I would expect to be the negative, although more usually brown and blue is the colour found for this one. It sounds like your machine might have been wired up incorrectly, or as already mentioned, you have a short on it somewhere. If you have a circuit tester, you will be able to check for and find the problem, starting by disconnecting the battery and checking your earth lead goes to earth ok and then check for shorting by testing across the battery leads and switching the switches to their various functions - something should show up if there is a fault. Can you charge the battery on a charger ok, or is the battery faulty and possibly causing the trouble?

Electric challenge

Posted: Mon Sep 01, 2014 10:07 am
by Nettshubby
Enfieldbang, my Reditch manual wiring diag does show red as positive, and goes straight to earth. However, the neg wire is shown as "brown and light". Does your ignition switch have the EMG, emergency position? If you run bike in this position for any length of time it could overcharge the battery, and if the earth connection on frame is bad, i suppose it would fry the wiring and battery?

Electric challenge

Posted: Tue Sep 02, 2014 11:04 am
by EnfieldbangDK
Thanks of all your relevant/interesting comments, very much appreciated. Kindly explain the EMG function... I have 3 settings: 1. No lights on 2. Lights on in the 2 small lights on the casquette plus tail/rear light 3. Lights on, with high/low beam plus tail/rear light. Thanks again and good vibrations to all.

Electric challenge

Posted: Tue Sep 02, 2014 11:28 am
by Nettshubby
I was assuming your bike had seperate ignition and lighting switches. Yours sounds as though it doesn't have an ignition switch. On the bikes whith the old lucas ignition switch, there was an Emergency start position for when you battery was flat, and this sent power straight to the coil for starting, and started the battery charging. You were only supposed to ride a short distance like this then switch over to normal.

Electric challenge

Posted: Tue Sep 02, 2014 8:01 pm
by Rasp
You need to check the connections on your light switch as the switch controls your lights and also switches in the coils in the alternator needed to run the lights and charge your battery. This is the way 6V systems were regulated. It may be wired so that all the coils are switched in all the time, which would mean that it would over charge if you were not using your head light. If it is wired this way it will probably work OK if you leave your headlight on all the time that you are riding (were you riding with your headlight off when you had the problem?). I think the smoking fuse and wiring you have since installing the new battery will be separate to your charging problem. Either you have melted more wires than you thought and caused a short or more probably you may have wired the both sides of the battery to ground as usually the positive, which will be wired to ground in a positive ground system, is usually red.